Indian Patents. 215824:AN IMPROVED PROCESS FOR THE PREPARATION OF ARALKYLATED AROMATIC COMPOUNDS

Title of Invention	AN IMPROVED PROCESS FOR THE PREPARATION OF ARALKYLATED AROMATIC COMPOUNDS
Abstract	This invention relates to an improved process for the preparation of aralkylated aromatic compounds. This invention particularly relates to a process for the aralkylation of aromatic compound by aromatic alkylating or aralkylating agent for preparing aralkylated aromatic compounds, using a supported solid catalyst.

Full Text	This invention relates to an improved process for the preparation of aralkylated aromatic compounds. This invention particularly relates to a process for the aralkylation of aromatic compound by aromatic alkylating or aralkylating agent for preparing aralkylated aromatic compounds, using a supported solid catalyst. This invention more particularly relates to a process for the aralkylation of aromatic compound by aromatic alkylating- or aralkylating agent for preparing aralkylated aromatic compounds, using a reusable and easily separable supported solid catalyst, comprising mixed metal oxides or halides deposited on a porous catalyst carrier or support, disclosed in our earlier patent application no. NF 98/98. The process for this invention could be used for the preparation of aralkylated aromatic compounds, which are fine chemicals and/or intermediates used in the preparation of fine chemicals. Aralkylated aromatic compounds are useful fine chemicals and these are also used as intermediates in a number of organic syntheses. Both the homogeneous and heterogeneous catalysed liquid phase processes for the preparation of aralkylated aromatic compounds are known in the prior ari. Homogeneous Acid Catiu sed Processes According to a US pat em. J.S. 3. 78,122 (1972), diphenyimeihane was prepai. . by treating a mixture of benzene and benzyl chloride with CuCl2. A US pater.US. 3,679,760(1972).disclosed the preparation of diaryl alkanes by refluxi .: benzyl C6H R.R2 (where R-.= H and R2= H, Ch3 or OH) and CuCl2. A French patent, Fr. Demande 2,144,578(1973), disclosed that substituted phenols p-RC6H4OH (where R=halogen or C1-4-alkyl) are benzylated by benzyl halides in th. presence of ZnCl2. A USSR patent, U.S.S.R. 394,353(1973), disclosea preparation of 2.6- and 2.4-(CH:,O:.. C6H3CH2C6H5 by treating m-(CH30)2C6H4 with benzyl chloride in the presence of catalyst at 145- 150°C, or SnCl2 catalyst at 165-170°C. A Japanese patent, Japan Kokai 7399,154(1973), disclosed preparation of dibenzyl benzene derivatives by benzylation of •"«««•,,,.,,.,. -,. n,^v* ... ., benzene or substituted benzenes using Friedel-Crafts catalyst e.g., A1C13, FeCl3 and 98% H2S04. According to this patent, 200 g α-methyl benzyl chloride was added to a refluxing mixture of 500 g benzene and 5 g A1C13 and the whole mixture refluxed for 5h to give 120 g α-methyl bezylbenzene. According to a German patent, Ger. Offen 2,456,747 (1976), o-benzyltoluenes were prepared in -90% yields by the reaction of a o-chloromethyltoluene with a benzene derivative in > 1:7 ratio in the presence of H2SO4 and/or H3PO4 and optionally 4-CH3C6H4SO3H, ZnCl2, BF3) etc. Thus 135 parts 85% H3PO4. 270 parts 85% H2S04, 10 parts 4-CH3C6H4SO3H, 70 pans 2CH3C6H4CH2C1 and 390 parts of C6H6 were heated at 75-80° C for 4h to give 89% 2- CH3C6H4CH2C6Hi5. An US Patent U.S. 4,049,733 (1977), disclosed preparation of diphanylmethane by benzylation of benzene with benzylether using phosphoric acid and optionally H2SO4 or a Friedel-Crafts type metal halidt. European patent. Eup.Pat.App; EP 37,628 (1981), disclosed preparation of diphenylmethan j by benzylation of benzene with chloromethylbenzenes in the resenco of 1: SO4 and a cationic surfactant or a non-ionic surfactar:i which is susceptible to protonation under strong acidic condit, ons. A German patent, Ger.Offen DE 3,922,518 (1991), disclosed a process for the manufacture of a-methylbenzylphenol derivatives, which comprises the treatment of C1-4-alkyl substitute.; phenols with styrene in the presence of phosphorus chloride catalyst. More recentlv, an European Patent, Eur.Pat.Appl.EP 538,704 (1 ;93), disclosed a process for the preparation of V. „„„,. • "! ' p- substituted o-benzylphenols by treating phenols, p-R C6H4OH (R = halo, alky I, OH, alkoxy, alkylmercapto, aryl, aryloxy or arylmercapto), with ArCH2X (Ar = corresponding aryl nucleus; X = halo, arylcarboxy, phenylsulfatoxy, hydroxy, alkoxy etc.) in a continuously functioning distillation apparatus in the presence of dissolved acid catalyst. The main disadvantages of the homogeneous acid catalyzed processes are as follows: 1) The separation and recovery of the dissolved acid catalysts from the liquid reaction mixture is difficult. 2) The disposal of the used acid catalysts creates environmental pollution. 3) The homogeneous acid catalysts also pose several other problems such as high toxicity, corrosion, spent acid disposal and use of more than the stoichiomeiric amount. Heterogeneous acid catalyzed processes i A German patent, Ger.Offen 2,547,030 (1977), disclosed the preparation of o-benzyl-toluenes by the reaction of o-methylbenzyl halides with substituted benzenes in the presence of Al-silicate. The 2-CH3C6H4CH2Cl was stirred with toluene and Al-silicate (25% A1203) at 110°C to give 81% 2-methylbenzyltoluene. According to a Japanese patent, Jpn. Kokai Tokkyo Koho JP 59,180,937 (1984), o-benzylphenol was prepared by the liquid ;-these reaction o: benzyl alcohol with phenol in the presence of γ-A!2O3. For example 7.5 g γ-AlO3 was aodeo : a mixture of 32.5 g benzyl alcohol and 47 g phenol at 90°C under stirring to give a product containing 49.9% o-benzyiphmol A German patent. Ger. Offen DE 37 (1988). disclosed the preparation of p-substituted o-ben/v]phero;s by benzylation 01 r-substitutec' phenols with ben :ylalcc ol 11: thu presence of Na-Y type zeolite. A mixture of .5 mole 4-C1C6H40H, 0.1 mole C6H5CH2OH and 0.6 g of Na-Y type zeolite was heated at 200°C for 3 hrs to give 25.4 % 2-benzyl-4-chlorophenol. A German patent, Ger. Offen DE 3,836,780 (1990), disclosed the process for the preparation of benzylbenzenes from benzenes and benzyl alcohols in the presence of activated bleaching earth and a diluent at 90-140°C. According to Japanese patent, Jpn Kokai Tokkyo Koho JP 03,170,442 (1991),>beTizylbiphenyls are manufactured by benzylating biphenyl and diphenylmethane with > 1 compound from benzyl halides, benzyl alcohol, benzyl ether in the presence of a zeolite or silica-alumina catalyst. An European patent, Eur.Pat. appl. EP 428,081 (1991), disclosed a process of benzylation of alkylbenzenes with benzyl chloride in the presence of H-Y or H-L zeolite catalyst. According to a German patent, Ger. Offen DE 4,038,933 (1992), disclosed a process for benzylation of aromatics using technical carbon catalysts. Aralkylation of aromatic compounds by aralkylating agent involves electrophilic substitution of H from the aromatic nucleus. It is well known in the prior an that the electrophilic substitution is favoured by the presence of electron donating groups, such as OH, alkyl, alkoxy, phenoxy, amine, alkyl amine, SH etc., in the aromatic compound to be aralkylated. Whereas in the absence of the electron donating groups, e.g. for benzene, naphthalene and anthracene, the aralkylation is relatively difficult [ref. G.A.Olah. in Friedel-Crafts and related reactions, Wiley-Interscience Publ., New York, 1963]. Although some limitations of the homogeneous acid catalyzed processes arc overcome by the prior art heterogeneous catalyzed processes described above, the araikylati:,.; activity of the solid catalysts used in the above processes are low, particularly fcr araikylating aromatic compounds not containing electron donating groups. Hence there is a p?a: practical need for developing a process for the aral'-\'!ation of aromatic comnounds with araikylating agent, using more efficient, easily separable and reusable solid catalyst. There is also a need for developing a catalytic process for the aralkylation of aromatic compounds not containing electron donating groups, usmg highly efficient, easily separable and reusable solid catalyst. Very recently, in our patent application no. NF 98/98, we have disclosed a supported solid catalyst, comprising mixed metal oxides or halides deposited on micro-, meso- or macroporous catalyst carrier or support, useful for Friedel-Crafts reactions and also a process for the preparation of this catalyst. The said catalyst is represented by a general formula: AaMZb(c)/S, wherein, A is selected from chemical elements Ga, Al, B, Zn, Fe, Sn, Ti, Th, Zr or a mixture of two or more thereof; M is selected from chemical elements In, TI or a mixture thereof; Z is selected from chemical elements 0, Cl, Br or I; S is porous catalyst support or carrier; a is AIM mole ratio in the range of about 0.001 to about 100; b is number of atoms of Z needed to fulfil the valence requirement of the metallic elements AaM present in the supported catalyst; c is weight percentage loading of AaMZb deposited on said catalyst support or carrier (S) in the range of about 0.5 to about 50. This invention is made with the following objects so that most of the drawbacks or limitations of the prior art homogeneous and heterogeneous catalyzed processes for the aralkylation of aromatic compounds could be overcome. The main object of the present invention is to provide an improv ed process preparation of aralkylated aromatic compound. Another object 01 mis :; ertion is to provide a liquid phase process for the aralkylation >f aromatic compound, with or without conu::n:n: electron donating groap. using a highly active supported solid catalyst on;rrisi::2 mixed nc: oxides or halides deposited on rn.cro-, me so- or macroporous catalyst came; or iuppori. • ;r: has high activity not only when the aromatic ring activating groups (i.e. electron donating groups such as alkyl, alkoxy, hydroxy, phenoxy, etc.) are present in the aromatic ring to be aralkylated but also when the ring activating group in the aromatic ring to be aralkylated is absent, so that the reaction temperature is low and/or time for completing the reaction is short; Other important object of this invention is to provide a liquid phase process for the aralkylation of aromatic compounds using said supported solid catalyst which is easily separable and reusable in the processs for several times. Another important object of this invention is to provide a solid catalyzed liquid phase process for the aralkylating aromatic compounds even in the presence of moisture in the reaction mixture. Accordingly, the present invention provides a process for the preparation of aralkylated aromatic compounds represented by a general chemical formula: (Formula Removed) by a liquid phase aralkylation of aromatic compounds, called substrates, represented by a general chemical formula: (Formula Removed) with aralkylating agents, represented by a general formula : (Formula Removed) Wherein Q is C6H1 or C10H3 or C14H5; M is C6H2 or Ci0H4 or C14H6; each of R1, R2, R3 and R, groups is H or CnH2n+i or CpH2p-1 or C6H5 or CnH2nC6H5 or OH or OCnH2n+1 or OC6H5 or halogen or CnH2n+1. XYX or N02 or NH2 or NHCnH2n+1, or N(CnH2n+1)2 or NHCOCnH2n+1 or NHCOC6H5 or CN or CHO or COOH or COO CnH2n+1 or CO CnH2n+1 or S03H or S03 CnH2n+1 or SH or alkyl mercapto group or aryl mercapto group; each of R5 and R6 group is H or CH3 or C2H5 or OH or OCH3 or OC2H5 or N02 or halogen or NH2; X is halogen or OH or S03H or COOH or OCnH2nC6H5 or O CnH2n+1 or aryl carboxy group or alkyl carboxy group, x is an integer between 1 and 2n+l and n & p are integers greater than or equal to 1 and 2 respectively, and C, H, N, 0 and S are chemical elements, using a supported solid catalyst comprising mixed metal oxides or halides deposited on porous catalyst carrier or support and represented by a general formula: wherein, A is selected from chemical elements Ga, Al, B, Zn, Fe, Sn, Ti, Th, Zr- or a mixture of two or more thereof; M is selected from chemical elements In, TI or a mixture thereof; Z is selected from chemical elements O, Cl, Br or I; S is porous catalyst support or carrier; a is A/M mole ratio in the range of about 0.001 to about 100; b is number of atoms of Z needed to fulfil the valence requirement of the metallic elements AaM present in the supported catalyst: c is weight percentage loading of AaMZb deposited on said catalyst support or carrier (S) in the range of about 0.5 to about 50. wherein, said process comprises: i) pretreating said solid catalyst at a temperature between 100°C and 800°C in a flow of moisture-free air or moisture free nitrogen at a gas hourly space velocity in the range 1000-20000 cm3g"1h-1 or under vacuum, for a period between 0. 1 h and 1 0 h , ii) contacting a liquid mixture of aromatic compound and aralkylating agent having a mole ratio of aromatic compound to aralkylating agent between 0.1 and 100, in the absence or presence of a moisture free nitrogen, with said pretreated supported solid catalyst at a weight ratio of said catalyst to aralkylating agent between 0.02 and 2.0 in a stirred batch reactor in the presence of an moisture free nitrogen bubbling through the reaction mixture and allowing the reaction to occur at a temperature between 25°C and 300°C at a pressure between 1 atm and 10 atm for a reaction period between 0.01 h and 50 h, iii) cooling the reaction mixture to a temperature about 25°C, removing said catalyst from the reaction mixture by filtration and then separating the reaction products from the reaction mixture by the known methods. Structural formula for said aralkylated aromatic compound represented by the chemical formula R1R2R3Er4CnH2nC6H3R5R6 is (Formula Removed) A structural formula for said aromatic compound represented by the chemical formula R1R2R3F4M is (Formula Removed) A structural formula for said aralkylating agent represented by the chemical formula XCnH2nC6H3R5R6 is (Formula Removed) In the process f the present invention, the preferred, reaction temperature may he between 40'JC and 20 'C; the preferred reaction :ure may be between 1 atm and 5 aim: the preferred rer.ction period may be between 0.05 a and 10 h; the preferred mole n:..;o of aromatic compound to aralkyiating a:gent may be between 1 and 2 the p-eferred weight ratio of catalyst 10 aralk :ting agent may be oeuveen 05 and 0.5; the "re:. red aror :,a.uc compound to b aralkylated may be benzene, higher aromatic hydrocarbon, hydroxy aromatic compound -, phenols, naphthols, etc), alkoxy aromatic compound or phenoxy aromatic compound (C6H5OC6H5, C10H7OC6H5, etc,); and the preferred group in the aralkylating agent may be halogen or OH; the preferred chemical element, A, in said catalyst may be selected from Ga, Zn, Fe or a mixture of two or more thereof; the preferred chemical element, Z, in said catalyst is O or Cl; the preferred percentage loading of the active catalyst mass on catalyst carrier, c, in said catalyst may be in the range of about 2 wt% to about 20 \vt%:and the preferred catalyst carrier or support, S, in the said catalyst may be selected from microporous silica gel, H-ZSM-5 or other pentasil (e.g. H-ZSM-8, H-ZSM-11, etc.) zeolite, mesoporous MCM-41 zeolite, montmorillonite clay, and meso- and/or macroporous catalyst carrier containing Si02, A1203, SiC, ZrO2, HfO2 or a mixture thereof. This invention provides a process for the preparation of aralkylated aromatic compounds represented by a general chemical formula: R^RsBUQCnlfcnCeHsRsRo, by a liquid phase aralkylation of aromatic compounds, called substrates, represented by a general chemical formula: RiR2R3R4M, with aralkylating agents, represented by a general formula : (Formula Removed) wherein Q is C6H1 or C10H3 or C14H5; M is C6H2 or CioH4 or C14H6; each of R1, R2, R3 and R4 groups is H or CnH2n+1 or CpH2p-1 or C6H5 or CnH2nC6H comprising mixed metal oxides or halides deposited on porous catalyst carrier or support and represented by a general formula: (Formula Removed) wherein, A is selected from chemical elements Ga, Al, B, Zn, Fe, Sn, Ti, Th, Zr or a mixture of two or more thereof; M is selected from chemical elements In, TI or a mixture thereof; Z is selected from chemical elements 0, Cl, Br or I; S is porous catalyst support or carrier; a is A/M mole ratio in the range of about 0.001 to about 100; b is number of atoms of Z needed to fulfil the valence requirement of the metallic elements AaM present in the supported catalyst; c is weight percentage loading of AaMZb deposited on said catalyst support or carrier (S) in the range of about 0.5 to about 50, disclosed in our earlier patent application no. NF 98/98; wherein, said process comprises: i) pretreating said solid catalyst at a temperature between 100°C and 800°C in a flow of moisture-free air or inert gas at a gas hourly space velocity in the range 1000 - 20000 cm3g-1'h-1 or under vacuum, for a period between 0.1 h and 10 h, ii) contacting a liquid mixture of aromatic compound and aralkylating agent having a mole ratio of aromatic compound to aralkylating agent between 0.1 and 100, in the absence or presence of a solvent, with said pretreated supported solid catalyst at a weidr ^atio of said catalyst to arakylating agent between 0.02 and 2.0 in a stirred batch reactor in the presence of an inert gas bubbling through the reaction mixture and allowing the reaction to occur at a temperature between 25°C and 300°C at a nressure between 1 arm and 10 atm for a reaction oerio.i between 0.01 hand 50 h, iii) cooling the reaction mixture to a temperature about 25°C, removing said catalyst from the reaction mixture by filtration and then separating the reaction products from the reaction mixture by the known methods. The main finding of this invention is that, the said catalyst shows high activity in the aralkylation of aromatic compounds not only when the electron donating group, which is aromatic ring activating group, is present in the aromatic ring to be aralkylated but also when the electron donating group is absent in the aromatic ring to be aralkylated and hence the reaction temperature is low and/or the time required for completing the reaction is short. Other important finding of this invention is that said solid catalyst can be separated easily and reused repeatedly in the process. Another important finding of this invention is that the aralkylation of aromatic compound over said catalyst occurs with high reaction rates even in the presence of moisture in the reaction mixture (i.e. a mixture of aromatic compound to be aralkylated, aralkylating agent, solid catalyst and solvent, if used). Yet another important finding of this invention is that the mechanism of the aralkylation of aromatic compounds over said solid catalyst is different from that of acid catalyzed Friedel-Crafts aralkylation reaction. Higher aromatic hydrocarbons may be aryl benzenes and alkyl or aryl polynuclear aromatic hydrocarbons. The process of this invention can be carried out in a stirred batch reactor, fitted with a reflux condenser and arrangement for bubbling inert gas through the reaction mixture, known in the prior art for carrying out liquid rmase reactions. In the process of this invention, the main products formed are aralkylated aromatic compound and a by-product HX, wherein H =. .lydrogen and X = halogen or OH or SO^H or COOH or OCnH2nC6H5 or OCnH2-1 or arylcarboxy group or alkylcarboxy group, depending upon said aralkylating agent used. In the process of this invention, aromatic compound and aralkylating agent are reactants and are converted partially or completely to said products. In the process of this invention, the role of said solvent, if used, is to dissolve solid reactant or reactants, to dilute reactants and/or to facilitate the reaction between aromatic compound and aralkylating agent. However, solvent may not be used in the process of this invention when both the reactants are liquid at said reaction conditions. Normally, said solvent is not converse! in the process of this invention. In the process of this invention, the role of inert gas bubbling continuously through the reaction mixture is to remove continuously said by-product from the reaction mixture so ±at the reverse reaction is avoided or minimised and the time required for completing the reaction is shortened. In the process of this invention, the role of the reflux condenser fitted with the reac:or is to condense reactants and solvents and to return them back to the reaction mixture and allow the inert gas, which is continuously bubbling through the reaction mixture, along with said byproduct to escape from the reaction mixture. In the process of this invention, the reaction pressure above atmospheric pressure may be used to allow the reaction to be carried out at temperature higher than the normal bc:iing point of the reactants and/or solvent, by increasing the boiling point of said reactants ^zd'or solvent with increasing the reaction pressure. Said catalyst, used in the process of this invention, is heterogeneous with respect :c the reaction mixture and can be removed from the reaction mixture simply by filtration and the removed catalyst, after washing with solvent or saici liquid aromatic compound, which is :o be aralkylated, can be reused in the said process. Said pretreatment to said catalyst in sten-i of the process of present inventen is necessary for removing moisture and other adsorbates adsorbed on the catalyst so that the catalyst shows its full efficiency for catalyzing the aralkylation reaction. The role of said catalyst is to activate both the reactants, aromatic compound and aralkylating agent. The R1R2C6H3CnH2n,----X bond of said aralkylating agent is weakened by its interaction with the catalyst, leading to the formation of a stable carbocation [RjR2C6H3CnH:n]+ (I) and X-. In the presence of said carbocation (I), said aromatic compound is activated on the said catalyst by weakening its bond between aromatic nucleus and H, leading to the formation of a penta-coordinated carbocation by the combination of said activated aromatic compound and said carbocation (I). The said penta-coordinated carbocation is then decomposed to an aralkylated aromatic compound, the main product of the reaction, and a proton, which combines with X~ to give HX, the by-product of the reaction. Zeolites are crystalline aluminosilicates containing well defined channels or pores of uniform diameter. A large number of microporous zeolites, such as X, Y, mordenite, L, beta, ZSM-5, ZSM-8. ZSM-11, etc., and mesoporous zeolites, such as M41S type material, e.g. MCM-41, are known in the prior-art [ ref. Breck in Zeolite Molecular Sieves, Wiley-Imerscience Dubl., New York, 1974; Beck and Co-workers. J.Am.Chem.Soc., vol.114, page 10S34,year 1992; Nature (London) vol.359, page 710, year 1992]. Montmorillonite :s a natural ciay having layered silicate structure and it is well known in the prior art 'Ref. R . Schoonheyiit "Clays: from two to three dimensions" in Studies in Surface Sc ence anc. Cataivsis, vol. 58, page 201-238 1991; and K. Ohtsuka, Chem. Mater., 9 (1^97) 2039-2051]. In general, micropores nave diameter below 1 nm; mesopores have diameter betv ce: about 1 nm and about 20 nm; and macropores have diameter above about 20 nm. S.iid cat::: st containing only microprres may be used in the process of this invention when both the reactants have minimum molecular diameter or critical size less than 0.7 nm. Whereas said catalyst containing meso and/or macropores may be used in the process of this invention for both small and large molecular size reactants. By the process of this invention, benzene and anthracene can be benzylated with benzyl chloride to corresponding benzylated aromatic compounds with 100% conversion of benzyl chloride, at a temperature of 80°C and 150°C, respectively and for a reaction period of 0.13 h and 0.3 h, respectively. The present invention is described with respect to the following examples illustrating the process of this invention for the aralkylation of aromatic compounds using supported soild catalysts. These examples are provided for illustrative purposes only and are not to be construed as limitations on the process of this invention. Definition of terms used in the examples Conversion of reactant (%) = mole % of the reactant converted to all products. All the ratios of aromatic compounds to aralkylating agent and of soh'ent to aralkylauing agent are mole ratios. The solid catalyst to aralkylating agent ratio is weight ratio. The flow rates of gases are measured at 0°C and 1 atm pressure. Gas hourly space velocity (GHSV) is volume of gas, measured at 0°C and 1 atm pressure, passed over unit mass of catalyst per htr.ir. Ac and Aa represent aromatic compound to be aralkylated and aralkylating agent, respectively. The rnicropores, mesopores and macronores have pore diameter of beiow 1.0 nm between about 1.0 nm and about 20 nm, and above about 20 nm, respectively. EXAMPLE-1 This example illustrates the process of this invention for the aralkylation of benzene, toluene, anisole and naphthalene by benzyl chloride or benzyl bromide to the corresponding benzylated aromatic compounds, using a Zn0.03TlO0.53 (20.4 wt%)/SZ5564 catalyst. The catalyst : Zn0.03TlO0.53 (20.4 wt%) / SZ5564 was prepared by impregnating a mixture of 0.1 g zinc acetate and 5.0 g thallous acetate, dissolved in 14 ml distilled water, on 20 g fine particles ( >100 mesh ) of SZ5564 catalyst support [obtained from M/s. NORTON Co. U.S.A., main chemical composition - 94.1 % (ZrO2 + HfO2), 3.5 % CaO, 1.6 % SiO2 and 0.41 % Al2O3; surface area = 0.1 m2g ~' ; porosity = 45 %] by incipient wetness technique, drying the impregnated mass in an air oven at 110°C for 10 h and calcining in air at 550°C for 4 h. The surface area of the catalyst was 0.22 m2g-'. The catalytic aralkylation reaction over the Zno.o3TlOo.53 (20.4 wt%) / SZ5564 was carried out by i) pretreating the catalyst in a quartz tubular reactor under a flow of moisture-free nitrogen at a gas hourly space velocity of 18,000 cm 3 g'1 h-1 at 500 °C for 1 h ,and then ii) contacting said pretreated catalyst with 15 cm3 liquid reaction mixture containing aromatic compound to be aralkylated and the aralkylating agent, benzyl chloride or benzyl bromide and optionally a solvent, n-heptane, in a stirred batch reactor (capacity : 50 cm3) fitted with a reflux condenser, mercury thermometer dipped in the reaction mixture and an inlet tube for passing gas through the reaction mixture, under vigorous stirring, while bubbling moisture-free N2 gas through the reaction mixture at the reaction conditions given in TABLE-1 and following the course of the reaction by measuring quantitatively the HC1 or HBr evolved during the reaction by absorbing it in aqueous NaOH solution by a simple acid-base titration using phenolrhthaiein indicator, and iii) cooling the reaction mixture to room temperature (25°C) and analysing the products and unconverted reactants present in the reaction mixture, after separating the solid catalyst from it by filtration, using chromatographic technique. The results are included in TABLE-1. TABLE-1 : Reaction conditions and results of the aralkylation of different aromatic compounds over the Zn0.o3TlOo.53 (20.4 wt%) SZ5564 catalyst. (Table Removed) Ac = Aromatic compound, Aa = Aralkylating agent EXAMPLE-2 This example illustrates the process of this invention for the aralkylation of benzene and higher aromatic hydrocarbons by benzyl chloride, benzyl alcohol or C6H5C4H8Cl, as an aralkylating agent, to corresponding aralkylated aromatic compounds, using Ga10.0InO16.5 (11-8 wt%)/SA5205 catalyst. The catalyst: Ga10.0InO16.5 (11.8 wt%) / SA5205 was prepared by impregnating a mixture of 2.8 g gallium nitrate and 0.33 g indium nitrate, dissolved in 7 ml distilled water, on 10 g SA5205 catalyst support (obtained from M/s. NORTON Co. U.S.A.), having main chemical composition : 11.8 % SiO2, 86.1 % A1203; surface area The catalytic aralkylation of benzene and higher aromatic hydrocarbons by benzyl chloride, benzyl alcohol or C6H5C4H8C1, over the Ga10.0InO16.5(11.8 wt%) / SA5205 catalyst was carried out by the procedure same as that described in EXAMPLE-1 at the reaction conditions given in TABLE-2. The results are included in TABLE-2. TABLE-2 : Reaction conditions and results of the aralkylation of different aromatic compounds over the Ga10.0InO16.5 (11.8 wt%)/SA 5205 catalyst. (Table Removed) Ac = Aromatic compound, Aa = Aralkylating agent EXAMPLE 3 This example illustrates the process of this invention for the aralkylation of benzene, higher aromatic hydrocarbon, anisole and phenol by benzyl chloride in the presence or absence of any solvent, over Ga12.6lnCl40.8(11.0 wt%)/Montmorillonite K10 catalyst. The Ga12.6lnCl40.8 (11 wt%) / Montmorrilonite K10 catalyst was prepared by impregnating a mixture of 0.1 g indium chloride and 1.0 g gallium chloride, dissolved in 17 ml moisture-free methanol, on 10 g Montmorillonite K10 clay (obtained from Aldrich Chemical Co. U.S.A.) by incipient wetness technique, drying the impregnated mass under vacuum at 100°C for 1 h and then calcining or heating further in a flow of pure helium at 150°C for 5 h. The catalytic aralkylation reactions over the catalyst was carried out by the procedure same as that described in EXAMPLE-1 at the reaction conditions given in TABLES-3 and 4, except that the catalyst pre-treatment was carried out under vacuum (2 torr pressure ) at 100 ~'C for 10 h. The results are included in TABLES-3 and 4. TABLE-3 : Reaction conditions and results of the aralkylation of different aromatic compounds over the Ga12.6InCl40.8 (11.0 wt%)/Montmorillonite Kl 0 catalyst. (Table Removed) Ac = Aromatic compound, Aa = Aralkylating agent TABLE-4 : Reaction conditions and results of the aralkylation of different aromatic compounds over the Ga12.6lnCl40.8(l 1.0 wt%)/Montmorillonite KIO catalyst. (Table Removed) Ac = Aromatic compound, Aa = Aralkylating agent EXAMPLE-4 This example illustrates the process of this invention for the aralkylation of benzene, toluene and anisole by benzyl bromide, using Ga11.0InO18.0 (2-3 wt%)/MCM-41 catalyst. The catalyst: Ga11.0InO18.0 (2.3 wt%) / MCM-41 was prepared by impregnating a mixture of 2.8 g gallium nitrate and 0.3 g indium nitrate, dissolved in 100 ml distilled water, on 50 g high silica meso-porous zeolite [prepared by the procedure described in the ref. Choudhary et al., Proceeding of Indian Academy of Sciences, (Chemical Sciences) volume 109, page 229 and year 1997], by incipient wetness technique, drying the impregnated mass in an air oven at 100°C for 20 h and calcining in air at 500°C for 4 h. The surface area of the catalyst was 1102 m2g -l. The catalytic aralkylation reaction over the catalyst was carried out by the procedure same as that described in EXAMPLE-1 at the reaction conditions given in TABLE-5, except that in the present case the pretreatment of the catalyst was carried out in the flow of moisture- free N2 at 700 ºC at a gas hourly space velocity of 3000 cm3 g-1 .h-1 for 0.5 h. The results are included in TABLE-5. TABLE-5 : Reaction conditions and results of the aralkylation of benzene and toluene and anisole over the Ga11.0InO18.0 (2.3 wt%)/MCM-41 catalyst. (Table Removed) Ac = Aromatic compound, Aa = Aralkylating agent EXAMPLE-5 This example illustrates the process of this invention for the aralkylation of benzene and methyl benzenes by benzyl chloride to corresponding aralkylated aromatic hydrocarbons, using Fe0.01Ga0.1InO1.665 (20 wt%)/MCM-41 catalyst. The Fe0.01Ga0.1InO1.665 (20 wt%)/MCM-41 catalyst was prepared by depositing a mixture of 21.7 g indium nitrate, 1.84 g gallium nitrate and 0.3 g ferric nitrate from their aquous solution on 50 g high silica MCM-41, prepared by the process described earlier [ref. Choudhary et al. Proc. Ind. Acad. Sci. (Chemical Sciences), 109 (1997) 229], by incipient wetness impregnation technique, drying the impregnated mass at 110°C for lOh and then calcining in an air oven at 550°C for 4h. The catalytic aralkylation of benzene and methyl benzenes by benzyl chloride over the above catalyst has been carried out by the procedure same as that described in EXAMPLE-1, at the reaction conditions given in TABLE-6. The results are presented in TABLE-6. TABLE-6 : Reaction conditions and results of the aralkylation of benzene, p-xylene and mesitylene over the Fe0.01Ga0.11nO1.665 (20 wt%)/ MCM-41 catalyst. (Table Removed) Ac = Aromatic compound, Aa = Aralkylating agent EXAMPLE-6 This example illustrates the process of this invention for the aralkylation of benzene, toluene and anisole by benzyl chloride, using Zn10Ga2.oInO5.5 (5 wt%)/HZSM-5 catalyst. The Zn1.oGa2.oIn05.5 (5 wt%)/HZSM-5 catalyst was prepared by depositing a mixture of 2.22 g zinc nitrate, 7.64 g gallium nitrate and 4.5 g indium nitrate from their .aquous solution on 100 g HZSM-5, having Si/Al ratio of 35.0, degree of H+exchange >99% and crystal size of 3-5 nm, by incipient weiness inpregnation technique, drying the inpregnated mass at 100°C for / 16 h and then calcining in an air oven at 550°C for 4 h. The aralkylation reactions were carried out using the above catalyst, by the procedure same as that described in EXAMPLE-1, except that the period of catalyst pretreatment was 0.2 h, at the reaction conditions given in TABLE-7. TABLE-7 : Reaction conditions and results of the aralkylation of benzene, tolune and anisole over the Zni.oGa2.0InO5.5 (5 wt%)/HZSM-5 catalyst. (Table Removed) Ac = Aromatic compound, Aa = Aralkylating agent EXAMPLE-7 This example illustrates the process of this invention for the aralkylation of benzene by benzyl chloride using a Ga0.05InO 1.575 (20 wt%)/SA5205 catalyst even when the moisture'is present in the reaction mixture and also reusing the catalyst number of times for subsequent batches of the aralkylation of benzene. The Ga0.05InO 1.575 (20 wt%)/SA5205 catalyst was prepared by depositing a mixture of 0.092 g gallium nitrate and 2.17 g indium nitrate from their aquous solution on 5 g macroporous SA5205 catalyst carrier, by incipient wetness impregnation technique, drying the impregnated mass at 120°C for 4 h and then calcining in an air oven at 600°C for 2 h. The aralkylation of benzene by benzyl chloride over the above catalyst was carried out by the procedure same as that described in EXAMPLE-1, except that in the present case the reaction was carried out using dry (moisture-free benzene) or wet benzene (benzene saturated with water) and also the catalyst used in the second and subsequent batches was obtained by filtration from the reaction mixture of the previous batch, at the reaction conditions given in TABLE-8. Before reusing the filtered catalyst, it was washed with benzene. The results are presented in TABLE-8. The results (TABLE-8) show that the catalyst of this invention catalyse: the aralkviation reaction even when water or moisture is present in the reaction mixture and ai-i the catai st can be reused repeatedly in the process of this invention, even for aralkyiating moisture containing benzene. TABLE-8 : Reaction conditions and results of the aralkylation of benzene, with or without containing moisture, by benzyl chloride over the Ga0.05InO 1.575 (20 wt%)/SA5205 catalyst. (Table Removed) Ac = Aromatic compound, Aa = Aralkylating agent The main advantages of the process of this invention over the prior art processes for the aralkylation of aromatic compound are as follows: 1) The process of this invention has a number of advantages over the earlier homogeneous catalysed processes for the preparation of aralkylated aromatic compounds, as follows: In the process of this invention, i) the catalyst used is heterogeneous solid catalyst and hence it can be separated from the reaction products simply by filtration , ii) the separated catalysts can be reused in the process for a number of times, and iii) also the catalyst is non corrosive, therefore most of the serious problems associated with homogeneous catalyst used in the earlier homogeneous catalysed processes for the preparation of aralkylated aromatic compounds are overcome in the process of this invention. 2) The process of this invention has also number of advantages over the prior art processes based on the use of solid catalyst for the aralkylation of aromatic compounds, as follows: i) The activity of the said catalyst used in the process of presem invention is much higher and hence the reaction is much faster and thereby the lime required for completing the reaction is much shorter. ii) The process of the present invention can be used for aralkyativ. both small and large size aromatic compounds with both small and large size aralkyiating agents to produce the corresponding aralkylated compounds, using said supported solid catalyst containing meso- or macroporous catalyst carrier. iii) In the process of this invention, since moisture-free inert gas is bubbled through the reaction mixture continuously, said by-product formed in the reaction is removed continuously and thereby the reverse aralkylation reaction is avoided or minimised, thus requiring shorter time for completing the reaction. iv) In the process of this invention, by using pressure higher than 1 atm, it is possible to carry out the aralkylation reaction at a temperature higher than the normal boiling point of either of the reactants and the solvent, and thereby the reaction period for completing the reaction is shortened and/or the inhibition of the reaction due to strong adsorption of the reactants, products or solvent on the catalyst is avoided or minimised. v) By the process of this invention, even the aralkylation of benzene, naphthalene or anthracene, which does not contain any aromatic ring activating electron donating group such as alkyl, alkoxy, hydroxy etc. group, at mild reaction conditions is rapid and hence accomplished at shorter reaction periods. vi) Moreover, using the supported solid catalyst of this invention, a rapid aralkylation of aromatic compound is possible even when the reaction mixture contains moisture; the catalyst is not deactivated by the presence of moisture in the reaction mixture. We claim: 1. A process for the preparation of aralkylated aromatic compounds represented by a general chemical formula: (Formula Removed) by a liquid phase aralkylation of aromatic compounds, called substrates, represented by a general chemical formula: (Formula Removed) with aralkylating agents, represented by a general formula: (Formula Removed) Wherein Q is C6H1 or C10H3 or C14H5; M is C6H2 or C10H4 or C14H6; each of R1, R2, R3 and R4 groups is H or CnH2n+1 or CpH2p-1 or C6H5 or CnH2nC6H5 or OH or OCnH2n+1 or OC6H5 or halogen or CnH2n+1.xYx or N02 or NH2 or NHCnH2n+1, or N(CnH2n+1)2 or NHCOCnH2n+, or NHCOC6H5 or CN or CHO or COOH or COO CnH2n+1 or CO CnH2n+1 or S03H or S03 CnH2n+1 or SH or alkyl mercapto group or aryl mercapto group; each of R5 and R6 group is H or CH3 or C2H5 or OH or OCH3 or OC2H5 or NO2 or halogen or NH2; X is halogen or OH or S03H or COOH or OCnH2nC6H5 or 0 CnH2n+1 or aryl carboxy group or alkyl carboxy group, x is an integer between 1 and 2n+l and n & p are integers greater than or equal to 1 and 2, respectively, and C, H, N, 0 and S are chemical elements, using a supported solid catalyst comprising mixed metal oxides or halides deposited on porous catalyst carrier or support and represented by a general formula: AaMZb(c)/S, wherein, A is selected from chemical elements Ga, Al, B, Zn, Fe, Sn, Ti, Th, Zr or a mixture of two or more thereof; M is selected from chemical elements In, TI or a mixture thereof: Z is selected from chemical elements O, Cl, Br or I; S is porous catalyst support or carrier; a is A/M mole ratio in the range of about 0.001 to about 100; b is number of atoms of Z needed to fulfil the valence requirement of the metallic elements AaM present in the supported catalyst; c is weight percentage loading of AaMZb deposited on said catalyst support or carrier (S) in the range of about 0.5 to about 50, wherein, said process comprises: i) pretreating said solid catalyst at a temperature between 100°C and 800°C in a flow of moisture-free air or moisture free nitrogen at a gas hourly space velocity in the range 1000 - 20000 cm3g-1h-1 or under vacuum, for a period between 0.1 h and 10 h, ii) contacting a liquid mixture of aromatic compound and aralkylating agent having a mole ratio of aromatic compound to aralkylating agent between 0.1 and 100. in the absence or presence of a n-heptane with said pretreated supported solid catalyst at a weight ratio of said catalyst to aralkylating agent between 0.02 and 2.0 in a stirred batch reactor in the presence of an moisture free nitrogen bubbling through the reaction mixture and allowing the reaction to occur at a temperature between 25 C and 300°C at a pressure between 1 atm and 10 atm for a reaction period between 0.01 h and 50 h, iii) cooling the reaction mixture to a temperature about 25°C, removing said catalyst from the reaction mixture by filtration and then separating the reaction products from the reaction mixture by the known methods. 2. A process as claimed in claim 1, wherein the reaction temperature preferably is between 40°Cand200°C. 3. A process as claimed in claims 1 to 2, wherein the preferred reaction pressure is between 1.0 atm and 5.0 atm. 4. A process as claimed in claims 1 to 3, wherein the preferred reaction period is between 0.05 h and 10 h. 5. A process as claimed in claims 1 to 4, wherein the preferred mole ratio of aromatic compound to aralkylating agent is between 1 and 20. 6. A process as claimed in claims 1 to 5, wherein the preferred weight ratio of said catalyst and aralkylating agent is between 0.05 and 0.5. 7. A process as claimed in claims 1 to 6, wherein the preferred aromatic compound to be aralkylated is benzene, higher aromatic hydrocarbon, hydroxy aromatic compound, alkoxy aromatic compound or phenoxy aromatic compound. 8. A process as claimed in claims 1 to 7, wherein the preferred group X of said aralkylating agent is Cl or OH. 9. A process as claimed in claims 1 to 8, wherein the preferred chemical element, A, in said catalyst is Ga, Zn, Fe or a mixture of two or more thereof. 10. A process as claimed in claims 1 to 9, wherein the preferred chemical element, Z, in said catalyst is O or Cl. 11. A process as claimed in claims 1 to 10, wherein the preferred percentage loading of the active catalyst mass on catalyst carrier, c, in said catalyst is in the range of about 2wt% to about 20wt%. 12. A process as claimed in claims 1 to 11, wherein the preferred catalyst carrier or support, S, in said catalyst is selected from H-ZSM-5 or other pentasil zeolite, mesoporous MCM-41 zeolite, microporous silica gel, montmorillonite clay and meso-and/or macroporous catalyst carriers containing SiO2, A12O3, SiC, ZrO2, HfO2 or a mixture thereof. 13. A Process for the preparation of of aralkylated aromatic compound using supported solid catalyst substantially as herein described with reference to examples.

Full Text

This invention relates to an improved process for the preparation of aralkylated aromatic compounds. This invention particularly relates to a process for the aralkylation of aromatic compound by aromatic alkylating or aralkylating agent for preparing aralkylated aromatic compounds, using a supported solid catalyst. This invention more particularly relates to a process for the aralkylation of aromatic compound by aromatic alkylating- or aralkylating agent for preparing aralkylated aromatic compounds, using a reusable and easily separable supported solid catalyst, comprising mixed metal oxides or halides deposited on a porous catalyst carrier or support, disclosed in our earlier patent application no. NF 98/98.
The process for this invention could be used for the preparation of aralkylated aromatic compounds, which are fine chemicals and/or intermediates used in the preparation of fine chemicals.
Aralkylated aromatic compounds are useful fine chemicals and these are also used as
intermediates in a number of organic syntheses. Both the homogeneous and heterogeneous
catalysed liquid phase processes for the preparation of aralkylated aromatic compounds are
known in the prior ari.
Homogeneous Acid Catiu sed Processes
According to a US pat em. J.S. 3. 78,122 (1972), diphenyimeihane was prepai. . by treating a mixture of benzene and benzyl chloride with CuCl2. A US pater.US. 3,679,760(1972).disclosed the preparation of diaryl alkanes by refluxi .: benzyl C6H R.R2 (where R-.= H and R2= H, Ch3 or OH) and CuCl2.
A French patent, Fr. Demande 2,144,578(1973), disclosed that substituted phenols p-RC6H4OH (where R=halogen or C1-4-alkyl) are benzylated by benzyl halides in th. presence of ZnCl2. A USSR patent, U.S.S.R. 394,353(1973), disclosea preparation of 2.6- and 2.4-(CH:,O:.. C6H3CH2C6H5 by treating m-(CH30)2C6H4 with benzyl chloride in the presence of

catalyst at 145- 150°C, or SnCl2 catalyst at 165-170°C. A Japanese patent, Japan Kokai 7399,154(1973), disclosed preparation of dibenzyl benzene derivatives by benzylation of
*•"«««•,,,.,,*.,. -,. n,^v* ... .,
benzene or substituted benzenes using Friedel-Crafts catalyst e.g., A1C13, FeCl3 and 98% H2S04. According to this patent, 200 g α-methyl benzyl chloride was added to a refluxing mixture of 500 g benzene and 5 g A1C13 and the whole mixture refluxed for 5h to give 120 g α-methyl bezylbenzene.
According to a German patent, Ger. Offen 2,456,747 (1976), o-benzyltoluenes were prepared in -90% yields by the reaction of a o-chloromethyltoluene with a benzene derivative in > 1:7 ratio in the presence of H2SO4 and/or H3PO4 and optionally 4-CH3C6H4SO3H, ZnCl2, BF3) etc. Thus 135 parts 85% H3PO4. 270 parts 85% H2S04, 10 parts 4-CH3C6H4SO3H, 70 pans 2CH3C6H4CH2C1 and 390 parts of C6H6 were heated at 75-80° C for 4h to give 89% 2-
CH3C6H4CH2C6Hi5.
An US Patent U.S. 4,049,733 (1977), disclosed preparation of diphanylmethane by benzylation of benzene with benzylether using phosphoric acid and optionally H2SO4 or a Friedel-Crafts type metal halidt.
European patent. Eup.Pat.App; EP 37,628 (1981), disclosed preparation of diphenylmethan j by benzylation of benzene with chloromethylbenzenes in the resenco of 1: SO4 and a cationic surfactant or a non-ionic surfactar:i which is susceptible to protonation under strong acidic condit, ons.
A German patent, Ger.Offen DE 3,922,518 (1991), disclosed a process for the manufacture of a-methylbenzylphenol derivatives, which comprises the treatment of C1-4-alkyl substitute.; phenols with styrene in the presence of phosphorus chloride catalyst. More recentlv, an European Patent, Eur.Pat.Appl.EP 538,704 (1 ;93), disclosed a process for the preparation of
V. „„„,. • "! '
p- substituted o-benzylphenols by treating phenols, p-R C6H4OH (R = halo, alky I, OH, alkoxy,

alkylmercapto, aryl, aryloxy or arylmercapto), with ArCH2X (Ar = corresponding aryl nucleus; X = halo, arylcarboxy, phenylsulfatoxy, hydroxy, alkoxy etc.) in a continuously functioning distillation apparatus in the presence of dissolved acid catalyst.
The main disadvantages of the homogeneous acid catalyzed processes are as follows:
1) The separation and recovery of the dissolved acid catalysts from the liquid reaction mixture
is difficult.
2) The disposal of the used acid catalysts creates environmental pollution.
3) The homogeneous acid catalysts also pose several other problems such as high toxicity,
corrosion, spent acid disposal and use of more than the stoichiomeiric amount.
Heterogeneous acid catalyzed processes i
A German patent, Ger.Offen 2,547,030 (1977), disclosed the preparation of o-benzyl-toluenes by the reaction of o-methylbenzyl halides with substituted benzenes in the presence of Al-silicate. The 2-CH3C6H4CH2Cl was stirred with toluene and Al-silicate (25% A1203) at 110°C to give 81% 2-methylbenzyltoluene. According to a Japanese patent, Jpn. Kokai Tokkyo Koho JP 59,180,937 (1984), o-benzylphenol was prepared by the liquid ;-these reaction o: benzyl alcohol with phenol in the presence of γ-A!2O3. For example 7.5 g γ-AlO3 was aodeo : a mixture of 32.5 g benzyl alcohol and 47 g phenol at 90°C under stirring to give a product containing 49.9% o-benzyiphmol A German patent. Ger. Offen DE 37 (1988). disclosed the preparation of p-substituted o-ben/v]phero;s by benzylation 01 r-substitutec' phenols with ben :ylalcc ol 11: thu presence of Na-Y type zeolite. A mixture of .5 mole 4-C1C6H40H, 0.1 mole C6H5CH2OH and 0.6 g of Na-Y type zeolite was heated at 200°C for 3 hrs to give 25.4 % 2-benzyl-4-chlorophenol.
A German patent, Ger. Offen DE 3,836,780 (1990), disclosed the process for the preparation of benzylbenzenes from benzenes and benzyl alcohols in the presence of activated

bleaching earth and a diluent at 90-140°C. According to Japanese patent, Jpn Kokai Tokkyo Koho JP 03,170,442 (1991),>beTizylbiphenyls are manufactured by benzylating biphenyl and diphenylmethane with > 1 compound from benzyl halides, benzyl alcohol, benzyl ether in the presence of a zeolite or silica-alumina catalyst. An European patent, Eur.Pat. appl. EP 428,081 (1991), disclosed a process of benzylation of alkylbenzenes with benzyl chloride in the presence of H-Y or H-L zeolite catalyst. According to a German patent, Ger. Offen DE 4,038,933 (1992), disclosed a process for benzylation of aromatics using technical carbon catalysts.
Aralkylation of aromatic compounds by aralkylating agent involves electrophilic substitution of H from the aromatic nucleus. It is well known in the prior an that the electrophilic substitution is favoured by the presence of electron donating groups, such as OH, alkyl, alkoxy, phenoxy, amine, alkyl amine, SH etc., in the aromatic compound to be aralkylated. Whereas in the absence of the electron donating groups, e.g. for benzene, naphthalene and anthracene, the aralkylation is relatively difficult [ref. G.A.Olah. in Friedel-Crafts and related reactions, Wiley-Interscience Publ., New York, 1963].
Although some limitations of the homogeneous acid catalyzed processes arc overcome by the prior art heterogeneous catalyzed processes described above, the araikylati:,.; activity of the solid catalysts used in the above processes are low, particularly fcr araikylating aromatic compounds not containing electron donating groups. Hence there is a p?a: practical need for developing a process for the aral'-\'!ation of aromatic comnounds with araikylating agent, using more efficient, easily separable and reusable solid catalyst. There is also a need for developing a catalytic process for the aralkylation of aromatic compounds not containing electron donating groups, usmg highly efficient, easily separable and reusable solid catalyst.

Very recently, in our patent application no. NF 98/98, we have disclosed a supported solid catalyst, comprising mixed metal oxides or halides deposited on micro-, meso- or macroporous catalyst carrier or support, useful for Friedel-Crafts reactions and also a process for the preparation of this catalyst. The said catalyst is represented by a general formula: AaMZb(c)/S,
wherein, A is selected from chemical elements Ga, Al, B, Zn, Fe, Sn, Ti, Th, Zr or a mixture of two or more thereof; M is selected from chemical elements In, TI or a mixture thereof; Z is selected from chemical elements 0, Cl, Br or I; S is porous catalyst support or carrier; a is AIM mole ratio in the range of about 0.001 to about 100; b is number of atoms of Z needed to fulfil the valence requirement of the metallic elements AaM present in the supported catalyst; c is weight percentage loading of AaMZb deposited on said catalyst support or carrier (S) in the range of about 0.5 to about 50.
This invention is made with the following objects so that most of the drawbacks or limitations of the prior art homogeneous and heterogeneous catalyzed processes for the aralkylation of aromatic compounds could be overcome.
The main object of the present invention is to provide an improv ed process preparation of aralkylated aromatic compound. Another object 01 mis :; ertion is to provide a liquid phase process for the aralkylation >f aromatic compound, with or without conu::n:n: electron donating groap. using a highly active supported solid catalyst on;rrisi::2 mixed nc: oxides or halides deposited on rn.cro-, me so- or macroporous catalyst came; or iuppori. • ;r: has high activity not only when the aromatic ring activating groups (i.e. electron donating groups such as alkyl, alkoxy, hydroxy, phenoxy, etc.) are present in the aromatic ring to be aralkylated but also when the ring activating group in the aromatic ring to be aralkylated is

absent, so that the reaction temperature is low and/or time for completing the reaction is short;
Other important object of this invention is to provide a liquid phase process for the aralkylation of aromatic compounds using said supported solid catalyst which is easily separable and reusable in the processs for several times.
Another important object of this invention is to provide a solid catalyzed liquid phase process for the aralkylating aromatic compounds even in the presence of moisture in the
reaction mixture.
Accordingly, the present invention provides a process for the preparation of aralkylated aromatic compounds represented by a general chemical formula:
(Formula Removed)
by a liquid phase aralkylation of aromatic compounds, called substrates, represented by a general
chemical formula:
(Formula Removed)
with aralkylating agents, represented by a general formula :
(Formula Removed)
Wherein Q is C6H1 or C10H3 or C14H5; M is C6H2 or Ci0H4 or C14H6; each of R1, R2, R3 and R, groups is H or CnH2n+i or CpH2p-1 or C6H5 or CnH2nC6H5 or OH or OCnH2n+1 or OC6H5 or halogen or CnH2n+1. XYX or N02 or NH2 or NHCnH2n+1, or N(CnH2n+1)2 or NHCOCnH2n+1 or NHCOC6H5 or CN or CHO or COOH or COO CnH2n+1 or CO CnH2n+1 or S03H or S03 CnH2n+1 or SH or alkyl mercapto group or aryl mercapto group; each of R5 and R6 group is H or CH3 or C2H5 or OH or OCH3 or OC2H5 or N02 or halogen or NH2; X is halogen or OH or S03H or COOH or OCnH2nC6H5 or O CnH2n+1 or aryl carboxy group or alkyl carboxy group, x is an integer between 1 and 2n+l and n & p are integers greater than or equal to 1 and 2

respectively, and C, H, N, 0 and S are chemical elements, using a supported solid catalyst comprising mixed metal oxides or halides deposited on porous catalyst carrier or support and represented by a general formula:
wherein, A is selected from chemical elements Ga, Al, B, Zn, Fe, Sn, Ti, Th, Zr- or a mixture of two or more thereof; M is selected from chemical elements In, TI or a mixture thereof; Z is selected from chemical elements O, Cl, Br or I; S is porous catalyst support or carrier; a is A/M mole ratio in the range of about 0.001 to about 100; b is number of atoms of Z needed to fulfil the valence requirement of the metallic elements AaM present in the supported catalyst: c is weight percentage loading of AaMZb deposited on said catalyst support or carrier (S) in the range of about 0.5 to about 50. wherein, said process comprises:
i) pretreating said solid catalyst at a temperature between 100°C and 800°C in a flow of moisture-free air or moisture free nitrogen at a gas hourly space velocity in the range 1000-20000 cm3g"1h-1 or under vacuum, for a period between 0. 1 h and 1 0 h ,
ii) contacting a liquid mixture of aromatic compound and aralkylating agent having a mole ratio of aromatic compound to aralkylating agent between 0.1 and 100, in the absence or presence of a moisture free nitrogen, with said pretreated supported solid catalyst at a weight ratio of said catalyst to aralkylating agent between 0.02 and 2.0 in a stirred batch reactor in the presence of an moisture free nitrogen bubbling through the reaction mixture and allowing the reaction to occur at a temperature between 25°C and 300°C at a pressure between 1 atm and 10 atm for a reaction period between 0.01 h and 50 h,

iii) cooling the reaction mixture to a temperature about 25°C, removing said catalyst from the reaction mixture by filtration and then separating the reaction products from the reaction mixture by the known methods.
Structural formula for said aralkylated aromatic compound represented by the chemical
formula R1R2R3Er4CnH2nC6H3R5R6 is
(Formula Removed)
A structural formula for said aromatic compound represented by the chemical formula R1R2R3F4M is
(Formula Removed)
A structural formula for said aralkylating agent represented by the chemical formula XCnH2nC6H3R5R6 is

(Formula Removed)

In the process f the present invention, the preferred, reaction temperature may he between 40'JC and 20 'C; the preferred reaction :ure may be between 1 atm and 5 aim: the preferred rer.ction period may be between 0.05 a and 10 h; the preferred mole n:..;o of aromatic compound to aralkyiating a:gent may be between 1 and 2 the p-eferred weight ratio of catalyst 10 aralk :ting agent may be oeuveen 05 and 0.5; the "re:. red aror :,a.uc compound to b aralkylated may be benzene, higher aromatic hydrocarbon, hydroxy aromatic compound -, phenols, naphthols, etc), alkoxy aromatic compound or phenoxy aromatic compound (C6H5OC6H5, C10H7OC6H5, etc,); and the preferred group in the aralkylating agent may be halogen or OH; the preferred chemical element, A, in said catalyst may be selected from Ga,
Zn, Fe or a mixture of two or more thereof; the preferred chemical element, Z, in said catalyst is O or Cl; the preferred percentage loading of the active catalyst mass on catalyst carrier, c, in said catalyst may be in the range of about 2 wt% to about 20 \vt%:and the preferred catalyst carrier or support, S, in the said catalyst may be selected from microporous silica gel, H-ZSM-5 or other pentasil (e.g. H-ZSM-8, H-ZSM-11, etc.) zeolite, mesoporous MCM-41 zeolite, montmorillonite clay, and meso- and/or macroporous catalyst carrier containing Si02, A1203, SiC, ZrO2, HfO2 or a mixture thereof.
This invention provides a process for the preparation of aralkylated aromatic compounds represented by a general chemical formula:
R^RsBUQCnlfcnCeHsRsRo,
by a liquid phase aralkylation of aromatic compounds, called substrates, represented by a
general chemical formula:
RiR2R3R4M,
with aralkylating agents, represented by a general formula :
(Formula Removed)
wherein Q is C6H1 or C10H3 or C14H5; M is C6H2 or CioH4 or C14H6; each of R1, R2, R3 and R4
groups is H or CnH2n+1 or CpH2p-1 or C6H5 or CnH2nC6H comprising mixed metal oxides or halides deposited on porous catalyst carrier or support and
represented by a general formula:
(Formula Removed)
wherein, A is selected from chemical elements Ga, Al, B, Zn, Fe, Sn, Ti, Th, Zr or a mixture of
two or more thereof; M is selected from chemical elements In, TI or a mixture thereof; Z is
selected from chemical elements 0, Cl, Br or I; S is porous catalyst support or carrier; a is A/M
mole ratio in the range of about 0.001 to about 100; b is number of atoms of Z needed to fulfil
the valence requirement of the metallic elements AaM present in the supported catalyst; c is
weight percentage loading of AaMZb deposited on said catalyst support or carrier (S) in the
range of about 0.5 to about 50, disclosed in our earlier patent application no. NF 98/98;
wherein, said process comprises:
i) pretreating said solid catalyst at a temperature between 100°C and 800°C in a flow of
moisture-free air or inert gas at a gas hourly space velocity in the range 1000 - 20000 cm3g-1'h-1
or under vacuum, for a period between 0.1 h and 10 h,
ii) contacting a liquid mixture of aromatic compound and aralkylating agent having a mole ratio
of aromatic compound to aralkylating agent between 0.1 and 100, in the absence or presence of
a solvent, with said pretreated supported solid catalyst at a weidr ^atio of said catalyst to
arakylating agent between 0.02 and 2.0 in a stirred batch reactor in the presence of an inert gas
bubbling through the reaction mixture and allowing the reaction to occur at a temperature
between 25°C and 300°C at a nressure between 1 arm and 10 atm for a reaction oerio.i between
0.01 hand 50 h,
iii) cooling the reaction mixture to a temperature about 25°C, removing said catalyst from the
reaction mixture by filtration and then separating the reaction products from the reaction
mixture by the known methods.

The main finding of this invention is that, the said catalyst shows high activity in the aralkylation of aromatic compounds not only when the electron donating group, which is aromatic ring activating group, is present in the aromatic ring to be aralkylated but also when the electron donating group is absent in the aromatic ring to be aralkylated and hence the reaction temperature is low and/or the time required for completing the reaction is short.
Other important finding of this invention is that said solid catalyst can be separated easily and reused repeatedly in the process. Another important finding of this invention is that the aralkylation of aromatic compound over said catalyst occurs with high reaction rates even in the presence of moisture in the reaction mixture (i.e. a mixture of aromatic compound to be aralkylated, aralkylating agent, solid catalyst and solvent, if used). Yet another important finding of this invention is that the mechanism of the aralkylation of aromatic compounds over said solid catalyst is different from that of acid catalyzed Friedel-Crafts aralkylation reaction.
Higher aromatic hydrocarbons may be aryl benzenes and alkyl or aryl polynuclear aromatic hydrocarbons.
The process of this invention can be carried out in a stirred batch reactor, fitted with a reflux condenser and arrangement for bubbling inert gas through the reaction mixture, known in the prior art for carrying out liquid rmase reactions.
In the process of this invention, the main products formed are aralkylated aromatic compound and a by-product HX, wherein H =. .lydrogen and X = halogen or OH or SO^H or COOH or OCnH2nC6H5 or OCnH2-1 or arylcarboxy group or alkylcarboxy group, depending upon said aralkylating agent used.
In the process of this invention, aromatic compound and aralkylating agent are reactants and are converted partially or completely to said products.

In the process of this invention, the role of said solvent, if used, is to dissolve solid reactant or reactants, to dilute reactants and/or to facilitate the reaction between aromatic compound and aralkylating agent. However, solvent may not be used in the process of this invention when both the reactants are liquid at said reaction conditions. Normally, said solvent is not converse! in the process of this invention.
In the process of this invention, the role of inert gas bubbling continuously through the reaction mixture is to remove continuously said by-product from the reaction mixture so ±at the reverse reaction is avoided or minimised and the time required for completing the reaction is shortened.
In the process of this invention, the role of the reflux condenser fitted with the reac:or is to condense reactants and solvents and to return them back to the reaction mixture and allow the inert gas, which is continuously bubbling through the reaction mixture, along with said byproduct to escape from the reaction mixture.
In the process of this invention, the reaction pressure above atmospheric pressure may be used to allow the reaction to be carried out at temperature higher than the normal bc:iing point of the reactants and/or solvent, by increasing the boiling point of said reactants ^zd'or solvent with increasing the reaction pressure.
Said catalyst, used in the process of this invention, is heterogeneous with respect :c the reaction mixture and can be removed from the reaction mixture simply by filtration and the removed catalyst, after washing with solvent or saici liquid aromatic compound, which is :o be aralkylated, can be reused in the said process.
Said pretreatment to said catalyst in sten-i of the process of present inventen is necessary for removing moisture and other adsorbates adsorbed on the catalyst so that the catalyst shows its full efficiency for catalyzing the aralkylation reaction.

The role of said catalyst is to activate both the reactants, aromatic compound and aralkylating agent. The R1R2C6H3CnH2n,----X bond of said aralkylating agent is weakened by its interaction with the catalyst, leading to the formation of a stable carbocation [RjR2C6H3CnH:n]+ (I) and X-. In the presence of said carbocation (I), said aromatic compound is activated on the said catalyst by weakening its bond between aromatic nucleus and H, leading to the formation of a penta-coordinated carbocation by the combination of said activated aromatic compound and said carbocation (I). The said penta-coordinated carbocation is then decomposed to an aralkylated aromatic compound, the main product of the reaction, and a proton, which combines with X~ to give HX, the by-product of the reaction.
Zeolites are crystalline aluminosilicates containing well defined channels or pores of uniform diameter. A large number of microporous zeolites, such as X, Y, mordenite, L, beta, ZSM-5, ZSM-8. ZSM-11, etc., and mesoporous zeolites, such as M41S type material, e.g. MCM-41, are known in the prior-art [ ref. Breck in Zeolite Molecular Sieves, Wiley-Imerscience Dubl., New York, 1974; Beck and Co-workers. J.Am.Chem.Soc., vol.114, page 10S34,year 1992; Nature (London) vol.359, page 710, year 1992]. Montmorillonite :s a natural ciay having layered silicate structure and it is well known in the prior art 'Ref. R . Schoonheyiit "Clays: from two to three dimensions" in Studies in Surface Sc ence anc. Cataivsis, vol. 58, page 201-238 1991; and K. Ohtsuka, Chem. Mater., 9 (1^97) 2039-2051].
In general, micropores nave diameter below 1 nm; mesopores have diameter betv ce: about 1 nm and about 20 nm; and macropores have diameter above about 20 nm. S.iid cat::: st containing only microprres may be used in the process of this invention when both the reactants have minimum molecular diameter or critical size less than 0.7 nm. Whereas said catalyst containing meso and/or macropores may be used in the process of this invention for both small and large molecular size reactants.

By the process of this invention, benzene and anthracene can be benzylated with benzyl chloride to corresponding benzylated aromatic compounds with 100% conversion of benzyl chloride, at a temperature of 80°C and 150°C, respectively and for a reaction period of 0.13 h and 0.3 h, respectively.
The present invention is described with respect to the following examples illustrating the process of this invention for the aralkylation of aromatic compounds using supported soild catalysts. These examples are provided for illustrative purposes only and are not to be construed as limitations on the process of this invention.
Definition of terms used in the examples
Conversion of reactant (%) = mole % of the reactant converted to all products. All the ratios of aromatic compounds to aralkylating agent and of soh'ent to aralkylauing agent are mole ratios. The solid catalyst to aralkylating agent ratio is weight ratio.
The flow rates of gases are measured at 0°C and 1 atm pressure. Gas hourly space velocity (GHSV) is volume of gas, measured at 0°C and 1 atm pressure, passed over unit mass of catalyst per htr.ir.
Ac and Aa represent aromatic compound to be aralkylated and aralkylating agent, respectively.
The rnicropores, mesopores and macronores have pore diameter of beiow 1.0 nm between about 1.0 nm and about 20 nm, and above about 20 nm, respectively.

EXAMPLE-1
This example illustrates the process of this invention for the aralkylation of benzene, toluene, anisole and naphthalene by benzyl chloride or benzyl bromide to the corresponding benzylated aromatic compounds, using a Zn0.03TlO0.53 (20.4 wt%)/SZ5564 catalyst.
The catalyst : Zn0.03TlO0.53 (20.4 wt%) / SZ5564 was prepared by impregnating a mixture of 0.1 g zinc acetate and 5.0 g thallous acetate, dissolved in 14 ml distilled water, on 20 g fine particles ( >100 mesh ) of SZ5564 catalyst support [obtained from M/s. NORTON Co. U.S.A., main chemical composition - 94.1 % (ZrO2 + HfO2), 3.5 % CaO, 1.6 % SiO2 and 0.41 % Al2O3; surface area = 0.1 m2g ~' ; porosity = 45 %] by incipient wetness technique, drying the impregnated mass in an air oven at 110°C for 10 h and calcining in air at 550°C for 4 h. The surface area of the catalyst was 0.22 m2g-'.
The catalytic aralkylation reaction over the Zno.o3TlOo.53 (20.4 wt%) / SZ5564 was carried out by i) pretreating the catalyst in a quartz tubular reactor under a flow of moisture-free nitrogen
at a gas hourly space velocity of 18,000 cm 3 g'1 h-1 at 500 °C for 1 h ,and then ii) contacting said pretreated catalyst with 15 cm3 liquid reaction mixture containing aromatic compound to be aralkylated and the aralkylating agent, benzyl chloride or benzyl bromide and optionally a solvent, n-heptane, in a stirred batch reactor (capacity : 50 cm3) fitted with a reflux condenser, mercury thermometer dipped in the reaction mixture and an inlet tube for passing gas through the reaction mixture, under vigorous stirring, while bubbling moisture-free N2 gas through the reaction mixture at the reaction conditions given in TABLE-1 and following the course of the reaction by measuring quantitatively the HC1 or HBr evolved during the reaction by absorbing it in

aqueous NaOH solution by a simple acid-base titration using phenolrhthaiein indicator, and
iii) cooling the reaction mixture to room temperature (25°C) and analysing the products and unconverted reactants present in the reaction mixture, after separating the solid catalyst from it by filtration, using chromatographic technique. The results are included in TABLE-1.

TABLE-1 : Reaction conditions and results of the aralkylation of different aromatic compounds over the Zn0.o3TlOo.53 (20.4 wt%) SZ5564 catalyst.

(Table Removed)
Ac = Aromatic compound, Aa = Aralkylating agent

EXAMPLE-2
This example illustrates the process of this invention for the aralkylation of benzene and higher aromatic hydrocarbons by benzyl chloride, benzyl alcohol or C6H5C4H8Cl, as an aralkylating agent, to corresponding aralkylated aromatic compounds, using Ga10.0InO16.5 (11-8 wt%)/SA5205 catalyst.
The catalyst: Ga10.0InO16.5 (11.8 wt%) / SA5205 was prepared by impregnating a mixture of 2.8 g gallium nitrate and 0.33 g indium nitrate, dissolved in 7 ml distilled water, on 10 g SA5205 catalyst support (obtained from M/s. NORTON Co. U.S.A.), having main chemical composition : 11.8 % SiO2, 86.1 % A1203; surface area The catalytic aralkylation of benzene and higher aromatic hydrocarbons by benzyl chloride, benzyl alcohol or C6H5C4H8C1, over the Ga10.0InO16.5(11.8 wt%) / SA5205 catalyst was carried out by the procedure same as that described in EXAMPLE-1 at the reaction conditions given in TABLE-2. The results are included in TABLE-2.

TABLE-2 : Reaction conditions and results of the aralkylation of different aromatic compounds over the Ga10.0InO16.5 (11.8 wt%)/SA 5205 catalyst.

(Table Removed)
Ac = Aromatic compound, Aa = Aralkylating agent

EXAMPLE 3
This example illustrates the process of this invention for the aralkylation of benzene, higher aromatic hydrocarbon, anisole and phenol by benzyl chloride in the presence or absence of any solvent, over Ga12.6lnCl40.8(11.0 wt%)/Montmorillonite K10 catalyst.
The Ga12.6lnCl40.8 (11 wt%) / Montmorrilonite K10 catalyst was prepared by impregnating a mixture of 0.1 g indium chloride and 1.0 g gallium chloride, dissolved in 17 ml moisture-free methanol, on 10 g Montmorillonite K10 clay (obtained from Aldrich Chemical Co. U.S.A.) by incipient wetness technique, drying the impregnated mass under vacuum at 100°C for 1 h and then calcining or heating further in a flow of pure helium at 150°C for 5 h.
The catalytic aralkylation reactions over the catalyst was carried out by the procedure same as that described in EXAMPLE-1 at the reaction conditions given in TABLES-3 and 4, except that the catalyst pre-treatment was carried out under vacuum (2 torr pressure ) at 100 ~'C for 10 h. The results are included in TABLES-3 and 4.

TABLE-3 : Reaction conditions and results of the aralkylation of different aromatic compounds over the Ga12.6InCl40.8 (11.0 wt%)/Montmorillonite Kl 0 catalyst.

(Table Removed)
Ac = Aromatic compound, Aa = Aralkylating agent

TABLE-4 : Reaction conditions and results of the aralkylation of different aromatic compounds over the Ga12.6lnCl40.8(l 1.0 wt%)/Montmorillonite KIO catalyst.

(Table Removed)
Ac = Aromatic compound, Aa = Aralkylating agent

EXAMPLE-4
This example illustrates the process of this invention for the aralkylation of benzene, toluene and anisole by benzyl bromide, using Ga11.0InO18.0 (2-3 wt%)/MCM-41 catalyst.
The catalyst: Ga11.0InO18.0 (2.3 wt%) / MCM-41 was prepared by impregnating a mixture of 2.8 g gallium nitrate and 0.3 g indium nitrate, dissolved in 100 ml distilled water, on 50 g high silica meso-porous zeolite [prepared by the procedure described in the ref. Choudhary et al., Proceeding of Indian Academy of Sciences, (Chemical Sciences) volume 109, page 229 and year 1997], by incipient wetness technique, drying the impregnated mass in an air oven at 100°C for 20 h and calcining in air at 500°C for 4 h. The surface area of the catalyst was 1102 m2g -l.
The catalytic aralkylation reaction over the catalyst was carried out by the procedure same as that described in EXAMPLE-1 at the reaction conditions given in TABLE-5, except that in the present case the pretreatment of the catalyst was carried out in the flow of moisture-
free N2 at 700 ºC at a gas hourly space velocity of 3000 cm3 g-1 .h-1 for 0.5 h. The results are included in TABLE-5.

TABLE-5 : Reaction conditions and results of the aralkylation of benzene and toluene and anisole over the Ga11.0InO18.0 (2.3 wt%)/MCM-41 catalyst.

(Table Removed)
Ac = Aromatic compound, Aa = Aralkylating agent

EXAMPLE-5
This example illustrates the process of this invention for the aralkylation of benzene and methyl benzenes by benzyl chloride to corresponding aralkylated aromatic hydrocarbons, using Fe0.01Ga0.1InO1.665 (20 wt%)/MCM-41 catalyst.
The Fe0.01Ga0.1InO1.665 (20 wt%)/MCM-41 catalyst was prepared by depositing a mixture of 21.7 g indium nitrate, 1.84 g gallium nitrate and 0.3 g ferric nitrate from their aquous solution on 50 g high silica MCM-41, prepared by the process described earlier [ref. Choudhary et al. Proc. Ind. Acad. Sci. (Chemical Sciences), 109 (1997) 229], by incipient wetness impregnation technique, drying the impregnated mass at 110°C for lOh and then calcining in an air oven at 550°C for 4h.
The catalytic aralkylation of benzene and methyl benzenes by benzyl chloride over the above catalyst has been carried out by the procedure same as that described in EXAMPLE-1, at the reaction conditions given in TABLE-6. The results are presented in TABLE-6.

TABLE-6 : Reaction conditions and results of the aralkylation of benzene, p-xylene and mesitylene over the Fe0.01Ga0.11nO1.665 (20 wt%)/ MCM-41 catalyst.

(Table Removed)
Ac = Aromatic compound, Aa = Aralkylating agent

EXAMPLE-6
This example illustrates the process of this invention for the aralkylation of benzene, toluene and anisole by benzyl chloride, using Zn10Ga2.oInO5.5 (5 wt%)/HZSM-5 catalyst.
The Zn1.oGa2.oIn05.5 (5 wt%)/HZSM-5 catalyst was prepared by depositing a mixture of 2.22 g zinc nitrate, 7.64 g gallium nitrate and 4.5 g indium nitrate from their .aquous solution on 100 g HZSM-5, having Si/Al ratio of 35.0, degree of H+exchange >99% and crystal size of 3-5 nm, by incipient weiness inpregnation technique, drying the inpregnated mass at 100°C for
/
16 h and then calcining in an air oven at 550°C for 4 h.
The aralkylation reactions were carried out using the above catalyst, by the procedure same as that described in EXAMPLE-1, except that the period of catalyst pretreatment was 0.2 h, at the reaction conditions given in TABLE-7.

TABLE-7 : Reaction conditions and results of the aralkylation of benzene,
tolune and anisole over the Zni.oGa2.0InO5.5 (5 wt%)/HZSM-5
catalyst.

(Table Removed)
Ac = Aromatic compound, Aa = Aralkylating agent

EXAMPLE-7
This example illustrates the process of this invention for the aralkylation of benzene by benzyl chloride using a Ga0.05InO 1.575 (20 wt%)/SA5205 catalyst even when the moisture'is present in the reaction mixture and also reusing the catalyst number of times for subsequent batches of the aralkylation of benzene.
The Ga0.05InO 1.575 (20 wt%)/SA5205 catalyst was prepared by depositing a mixture of 0.092 g gallium nitrate and 2.17 g indium nitrate from their aquous solution on 5 g macroporous SA5205 catalyst carrier, by incipient wetness impregnation technique, drying the impregnated mass at 120°C for 4 h and then calcining in an air oven at 600°C for 2 h.
The aralkylation of benzene by benzyl chloride over the above catalyst was carried out by the procedure same as that described in EXAMPLE-1, except that in the present case the reaction was carried out using dry (moisture-free benzene) or wet benzene (benzene saturated with water) and also the catalyst used in the second and subsequent batches was obtained by filtration from the reaction mixture of the previous batch, at the reaction conditions given in TABLE-8. Before reusing the filtered catalyst, it was washed with benzene. The results are presented in TABLE-8.
The results (TABLE-8) show that the catalyst of this invention catalyse: the aralkviation reaction even when water or moisture is present in the reaction mixture and ai-i the catai st can be reused repeatedly in the process of this invention, even for aralkyiating moisture containing benzene.

TABLE-8 : Reaction conditions and results of the aralkylation of benzene, with or without containing moisture, by benzyl chloride over the Ga0.05InO 1.575 (20 wt%)/SA5205 catalyst.

(Table Removed)
Ac = Aromatic compound, Aa = Aralkylating agent

The main advantages of the process of this invention over the prior art processes for the aralkylation of aromatic compound are as follows:
1) The process of this invention has a number of advantages over the earlier homogeneous catalysed processes for the preparation of aralkylated aromatic compounds, as follows: In the process of this invention,
i) the catalyst used is heterogeneous solid catalyst and hence it can be separated from the reaction products simply by filtration ,
ii) the separated catalysts can be reused in the process for a number of times, and iii) also the catalyst is non corrosive, therefore most of the serious problems associated with homogeneous catalyst used in the earlier homogeneous catalysed processes for the preparation of aralkylated aromatic compounds are overcome in the process of this invention.
2) The process of this invention has also number of advantages over the prior art processes based on the use of solid catalyst for the aralkylation of aromatic compounds, as follows:
i) The activity of the said catalyst used in the process of presem invention is much
higher and hence the reaction is much faster and thereby the lime required for
completing the reaction is much shorter.
ii) The process of the present invention can be used for aralkyativ. both small and large
size aromatic compounds with both small and large size aralkyiating agents to produce
the corresponding aralkylated compounds, using said supported solid catalyst
containing meso- or macroporous catalyst carrier.
iii) In the process of this invention, since moisture-free inert gas is bubbled through the
reaction mixture continuously, said by-product formed in the reaction is removed

continuously and thereby the reverse aralkylation reaction is avoided or minimised, thus
requiring shorter time for completing the reaction.
iv) In the process of this invention, by using pressure higher than 1 atm, it is possible to
carry out the aralkylation reaction at a temperature higher than the normal boiling point
of either of the reactants and the solvent, and thereby the reaction period for completing
the reaction is shortened and/or the inhibition of the reaction due to strong adsorption of
the reactants, products or solvent on the catalyst is avoided or minimised.
v) By the process of this invention, even the aralkylation of benzene, naphthalene or
anthracene, which does not contain any aromatic ring activating electron donating group
such as alkyl, alkoxy, hydroxy etc. group, at mild reaction conditions is rapid and hence
accomplished at shorter reaction periods.
vi) Moreover, using the supported solid catalyst of this invention, a rapid aralkylation of
aromatic compound is possible even when the reaction mixture contains moisture; the
catalyst is not deactivated by the presence of moisture in the reaction mixture.

We claim:
1. A process for the preparation of aralkylated aromatic compounds represented by a general chemical formula:
(Formula Removed)
by a liquid phase aralkylation of aromatic compounds, called substrates, represented by a general chemical formula:
(Formula Removed)
with aralkylating agents, represented by a general formula:
(Formula Removed)
Wherein Q is C6H1 or C10H3 or C14H5; M is C6H2 or C10H4 or C14H6; each of R1, R2, R3 and R4 groups is H or CnH2n+1 or CpH2p-1 or C6H5 or CnH2nC6H5 or OH or OCnH2n+1 or OC6H5 or halogen or CnH2n+1.xYx or N02 or NH2 or NHCnH2n+1, or N(CnH2n+1)2 or NHCOCnH2n+, or NHCOC6H5 or CN or CHO or COOH or COO CnH2n+1 or CO CnH2n+1 or S03H or S03 CnH2n+1 or SH or alkyl mercapto group or aryl mercapto group; each of R5 and R6 group is H or CH3 or C2H5 or OH or OCH3 or OC2H5 or NO2 or halogen or NH2; X is halogen or OH or S03H or COOH or OCnH2nC6H5 or 0 CnH2n+1 or aryl carboxy group or alkyl carboxy group, x is an integer between 1 and 2n+l and n & p are integers greater than or equal to 1 and 2, respectively, and C, H, N, 0 and S are chemical elements, using a supported solid catalyst comprising mixed metal oxides or halides deposited on porous catalyst carrier or support and represented by a general formula: AaMZb(c)/S,
wherein, A is selected from chemical elements Ga, Al, B, Zn, Fe, Sn, Ti, Th, Zr or a mixture of two or more thereof; M is selected from chemical elements In, TI or a mixture thereof: Z is

selected from chemical elements O, Cl, Br or I; S is porous catalyst support or carrier; a is A/M mole ratio in the range of about 0.001 to about 100; b is number of atoms of Z needed to fulfil the valence requirement of the metallic elements AaM present in the supported catalyst; c is weight percentage loading of AaMZb deposited on said catalyst support or carrier (S) in the range of about 0.5 to about 50, wherein, said process comprises:
i) pretreating said solid catalyst at a temperature between 100°C and 800°C in a flow of moisture-free air or moisture free nitrogen at a gas hourly space velocity in the range 1000 - 20000 cm3g-1h-1 or under vacuum, for a period between 0.1 h and 10 h,
ii) contacting a liquid mixture of aromatic compound and aralkylating agent having a mole ratio of aromatic compound to aralkylating agent between 0.1 and 100. in the absence or presence of a n-heptane with said pretreated supported solid catalyst at a weight ratio of said catalyst to aralkylating agent between 0.02 and 2.0 in a stirred batch reactor in the presence of an moisture free nitrogen bubbling through the reaction mixture and allowing the reaction to occur at a temperature between 25 C and 300°C at a pressure between 1 atm and 10 atm for a reaction period between 0.01 h and 50 h,
iii) cooling the reaction mixture to a temperature about 25°C, removing said catalyst from the reaction mixture by filtration and then separating the reaction products from the reaction mixture by the known methods.
2. A process as claimed in claim 1, wherein the reaction temperature preferably is between
40°Cand200°C.
3. A process as claimed in claims 1 to 2, wherein the preferred reaction pressure is between 1.0 atm
and 5.0 atm.

4. A process as claimed in claims 1 to 3, wherein the preferred reaction period is between 0.05 h
and 10 h.
5. A process as claimed in claims 1 to 4, wherein the preferred mole ratio of aromatic compound to
aralkylating agent is between 1 and 20.
6. A process as claimed in claims 1 to 5, wherein the preferred weight ratio of said catalyst and
aralkylating agent is between 0.05 and 0.5.
7. A process as claimed in claims 1 to 6, wherein the preferred aromatic compound to be
aralkylated is benzene, higher aromatic hydrocarbon, hydroxy aromatic compound, alkoxy
aromatic compound or phenoxy aromatic compound.
8. A process as claimed in claims 1 to 7, wherein the preferred group X of said aralkylating agent is
Cl or OH.
9. A process as claimed in claims 1 to 8, wherein the preferred chemical element, A, in said
catalyst is Ga, Zn, Fe or a mixture of two or more thereof.
10. A process as claimed in claims 1 to 9, wherein the preferred chemical element, Z, in said
catalyst is O or Cl.
11. A process as claimed in claims 1 to 10, wherein the preferred percentage loading of the active
catalyst mass on catalyst carrier, c, in said catalyst is in the range of about 2wt% to about 20wt%.
12. A process as claimed in claims 1 to 11, wherein the preferred catalyst carrier or support, S, in
said catalyst is selected from H-ZSM-5 or other pentasil zeolite, mesoporous MCM-41 zeolite,
microporous silica gel, montmorillonite clay and meso-and/or macroporous catalyst carriers
containing SiO2, A12O3, SiC, ZrO2, HfO2 or a mixture thereof.

13. A Process for the preparation of of aralkylated aromatic compound using supported solid catalyst substantially as herein described with reference to examples.

Documents:

2526-del-1998-abstract.pdf

2526-del-1998-claims.pdf

2526-del-1998-correspondence-others.pdf

2526-del-1998-correspondence-po.pdf

2526-del-1998-description (complete).pdf

2526-del-1998-form-1.pdf

2526-del-1998-form-19.pdf

2526-del-1998-form-2.pdf

2526-del-1998-form-3.pdf

2526-del-1998-petition-138.pdf

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Patent Number

215824

Indian Patent Application Number

2526/DEL/1998

PG Journal Number

12/2008

Publication Date

21-Mar-2008

Grant Date

04-Mar-2008

Date of Filing

26-Aug-1998

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI-110 001, INDIAN.

Inventors:

#	Inventor's Name	Inventor's Address
1	DR. VASANT RAMCHANDRA CHOUDHARY	NATIONAL CHEMICAL LABORATORY, PUNE-8.
2	MR. SUMAN KUMAR JANA	NATIONAL CHEMICAL LABORATORY, PUNE-8.
3	MR. B-PHANI KIRAN	NATIONAL CHEMICAL LABORATORY, PUNE-8.

PCT International Classification Number

C07C 41/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA