Title of Invention

PROCESS FOR PREPARATION OF 3, 5 DICHLOROANILINE

Abstract

The present invention disclosed process for preparation of 3, 5 dichloroaniline. A process for producing 3, 5 dichloroaniline comprising (a) bromination of dichloro benzene or mixed dichloro benzene to produce dichloro bromo benzene (b) isomerization of dichloro bromo benzene and separation of 3, 5 dichloro bromo benzene and (c) amonolysis of 3, 5 dichloro bromo benzene to produce 3, 5 dichloroaniline. 90 to 94% bromine is recovered from 42 to 48% hydrobromic acid and sodium bromide. Production of 3, 5 dichloroaniline is at very low cost and without creating much pollution.

Full Text

FORM 2 THE PATENT ACT 1970 (39 of 1970) & The Patents Rules, 2003 COMPLETE SPECIFICATION (See section 10 and rule 13) 1. TITLE OF THE INVENTION PROCESS FOR PREPARATION OF 3, 5 DICHLORO ANILINE 2. APPLICANT (S) (a) NAME: Shah Dipakkumar Bhanuchandra (b)NATIONALITY: an Indian (c) ADDRESS: 901, Neptune Tower, Asopalav Complex, Chharwada Road, Vapi-396191, Gujarat, India. 3. PREMABLE TO THE DESCRIPTION PROVISIONAL The following specification describes the invention. COMPLETE The following specification particularly describes the invention and the manner in which it is to be performed. The present invention relates to process for preparation of 3, 5 dichloroaniline. In the present invention 3, 5 dichloroaniline is produce in three steps (a) bromination of dichloro benzene or mixed dichloro benzene to produce dichloro bromo benzene (b) isomerization of dichloro bromo benzene and separation of 3, 5 dichloro bromo benzene and (c) amonolysis of 3, 5 dichloro bromo benzene to produce 3, 5 dichloroaniline. Background of the Invention 3, 5-dichloroaniline (dichloro-substitued aniline at 3 and 5 positions) is a white-brown solid with aromatic odor; melts at 52° C, boils at 261° C; insoluble in water but readily soluble in most organic solvents. It is used as an intermediate in the production of a number of products, including agricultural chemicals, azo dyes and pigments and pharmaceuticals. There are some patents which disclosed method for preparation of 1 -bromo 2-4 dichlorobenzene. In US4138436 1-bromo 2-4 dichlorobenzene is obtained by reacting metadichlorobenzene with bromine at about 10° to 40° C in the presence of A1C13 or FeCl3. Further the 1-bromo 2-4 dichlorobenzene is added to liquid ammonia in which a specific metal amide is dispersed. In US4347390 m-dichlorobenzene, p-dichlorobenzene or a mixture of dichlorobenzene is brominated by adding bromine in presence of an aluminum halide. Then isomerizing the product bromodichlorobenzene is done and final product 1-bromo 3, 5 dichlorobenzene is obtained. There are some patents which disclosed method for preparation of 3,5 dichloroaniline. US7176334 disclosed a process for the preparation of substituted halogenated anilines in which 3,5 dichloroaniline is prepared by (a) reacting 1,3,5-trichlorobenzen with benzophenone imine in presence of a palladium catalyst complex which comprised l,l-bis(diphenylphosphino) ferrocene (dppf) or 1,4-bis-diphenylphosphinobutane (dppb) to form an intermediate imine and (b) hydrolyzing with acid the intermediate to form 3,5-dichloroaniline. This in this invention reaction is carried out in presence of imine and a transition metal catalyst. CN1690040 disclosed preparation process of 3, 5-dichloroaniline in which 4-chloro-2-nitrotoluene produced in the production of 6-chloro-2-nitrotoluene as material is first chlorinated, rectified and separated to obtain 4, 6-dichloro o-nitrotoluene; 4, 6-dichloro o-nitrotoluene is then oxidized and hydrogenation reduced to obtain 4, 6-dichloro amino benzoic acid; and 4, 6-dichloro amino benzoic acid is decarboxylated to obtain the product 3, 5-dichloro aniline. The present invention has total yield of about 70 % JP57200334 disclosed preparation of 3, 5 dichloroaniline in which 5-chloroisophthaloyl chloride is used as a raw material and is subjected to the partial decarbonylation reaction to obtain 3,5 dichlorobenzoyl chloride, which is amidated with ammonia or ammonia water to obtain 3,5 dichlorobenzamide. The objective 3,5 dichloroaniline is prepared from the 3,5 dichlorobenzamide by reacting with a hypohalous acid alkali metal salt or alkaline earth metal salt, and hydrolyzing the product. The compound used as a raw material can be prepared at an extremely low cost, in high yield, by reacting isophthaloyl chloride with chlorine. GB1478133 disclosed process for preparation of an aniline which is meta-substituted by chlorine. In this 3, 5 dichloroaniline is prepared using 2, 5-dichloronianline reacting with hydrogen in solution in a neutral or acid medium in presence of a noble metal which is in elementary form and in the presence of sulphur, an organic sulphur compound or an inorganic monosulphide, polysulphide, thiosulphide or thiocynate at an elevated temperature and pressure. US4340759, US4324914, US4532350 & US4351959 disclosed process for preparation of anilines substituted by chlorine in the meta position comprising reacting aniline/nitrobenzene polysubstituted by chlorine with hydrogen, under heat, in presence of ions, liquid medium at particular temperature and low pressure. US4085141 described method of preparing a meta-chloroaniline by contacting substituted aniline containing a chlorine substituent at other than a meta-position and a chlorine substituent at the meta position with hydrogen in solution in an acid medium in the presence of a noble metal catalyst at elevated temperature and pressure. In US5965775 3, 5 difluoroaniline is prepared from reacting 3,5 difluorochlorobenze with ammonia in presence of a solvent, copper compound and at least one metal selected from the group consisting of copper, iron, cobalt, nickel, chromium, molybdenum and zinc at 100 to 250 °C. In US4508922 halogenated benzene especially molohalogenobenzenes upto hexahalogenobenzenes, in particular trihalogenobensenes and very particularly 1, 3, 5-trihalogenobenzenes are subjected to ammonolysis with aqueous ammonia solution in the presence of copper and 8-hydroquinoline for the preparation of 3, 5-dichloroaniline. In existing commercial route, 2,6 dichloro para nitro aniline is diazotized with sulphuric acid and sodium nitrite. Then it is reacting with reducing agent like methanol, formic acid, formaldehyde etc. The resulting product is 3,5 dichloro nitro benzene. Then it is reduce with iron and acid or caustic and sulphar or hydrogen. The resulting product is 3, 5 dichloroaniline. All above method are costly and create much pollution so there is a need of method which is cheaper and create less pollution. Objects of the Invention: The main object of the present invention is to produce 3, 5 dichloroaniline from 1, 3 dichloro benzene or 1, 4 dichloro benzene or mixed dichloro benzene {1, 3 dichloro benzene (m-dichlorobenzene) and 1, 4 dichloro benzene( p-dichlorobenzene) }. 1,4 dichloro benzene and mixture of m-dichloro benzene and p-dichloro benzene is cheaper than pure m-dichloro benzene. An object of the present invention is 90 to 94% recovery of bromine which is high value reactant in whole process. Another object of the invention is to produce 3, 5 dichloroaniline at very low cost. A further object of the current invention is to produce 3, 5 dichloroaniline with high yield and without creating much pollution. An additional object of the invention is that HBr generated during the process is scrubbed and use to make 42 to 48 % commercial hydrobromic Acid. Yet another object of the invention is that aluminum chloride converted in to aluminum chloride solution during the process which can be used to make poly aluminum chloride (PAC). Furthermore object of the invention is that at decided temperature and pressure, only bromo is replaced. Chloro required high pressure and temperature compare to bromo for replacement. So it is easy to get selectivity for replacement of bromo with amino. Summary Of The Invention: The present invention disclosed process for preparation of 3, 5 dichloroaniline. A process for producing 3, 5 dichloroaniline comprising (a) bromination of dichloro benzene or mixed dichloro benzene to produce dichloro bromo benzene (b) isomerization of dichloro bromo benzene and separation of 3, 5 dichloro bromo benzene and (c) amonolysis of 3, 5 dichloro bromo benzene to produce 3, 5 dichloroaniline. Detailed Description: The nature of the invention and the manner in which it is to be performed is clearly described in the specification. The invention has various components and they are clearly described in the following pages of complete specification. The process for preparation of 3, 5 dichloroaniline comprising following steps: Step -1 : Formation of dichloro bromo benzene from dichloro benzene 1. m-dichloro benzene or p- dichloro benzene or mixture of m-dichloro benzene and p-dichloro benzene is taken in glass flask. 2-5 % aluminium chloride/ ferric chloride and bromine is slowly added at the temperature range of 10 -50°C and stirred. 2. Generated HBr gas is scrubbed in water to make 40 to 48 % strength of hydrobromic acid. 3. After completion the addition of bromine the mixture obtained in step (2) is stirred for half an hour. After completion of one whole reaction 15-35 % dichlorobenzene, 40 -65% dichlorobromobenzene and 2 - 10 % dichlorodibromo benzene is obtained. Then it is recycled to obtain maximum amount of dichloro bromo benzene. The yield of dichlorobromo benzene against dichloro benzene is 93 to 94%. STEP - II Isomerization of dichloro bromo benzene 1. Dichlorobromobenzene and aluminum chloride is mixed and heated up to 100 -280 °C for 4- 10 hours. 2. Cooled down up to room temperature. 3. 3, 5 dichloro bromo benzene is optionally distillated and crystallized before next step. The conversion of 3, 5 dichloro bromobenzene is 40 % to 50 %. STEP - III Amonolysis : 1. 3, 5 dichloro bromo benzene is taken and charged with cuprous chloride/cuprous oxide and ammonia solution in water of min 20 % strength (w/w). 2. Then it is heated up to 120 -250° C at 10 -80 kg/cm2 pressure for 2 - 15 hours. 3. It is cooled down up to 80 -90° C and excess ammonia gas is recovered. 4. Further it is cooled down up to 35- 40° C. 5. 7 to 8 gm NaOH is added and heated up to 50- 100° C to recover the ammonia from ammonium bromide. 6. The mass is cooled down up to 30- 35° C for one hour. 7. Solvent is added and stirred for half an hour then allowed it to settle down. 8. The solvent layer and aqueous layer are separated out. 9. Both the layers are filtered. The cuprous chloride remains on filter. It may be reuse. 10.3, 5 dichloroaniline is separated out by distillation and crystallization. The yield of 3, 5 dichloroaniline will be 80% against the conversion of 3, 5 dichlorobromo benzene. The temperature range uses for formation of dichloro bromo benzene from dichloro benzene more preferably is 20 - 60 ° C. The temperature range use for isomerization more preferably is 120-220° C. Aluminum chloride use for isomerization of dichloro bromo benzene is 40 - 80 gm. Solvent may be propanol, butanol, pentanol, ethyl acetate, toluene, o-dichloro benzene, butyl acetate, n-ethyl diisopropyl amine. In the first step hydrobromic acid is generated. To recover bromine from that, take 100 gm hydrobromic acid in glass flask which is to be equipped with stirring assembly, condensation system, sparger & scrubber. Brine temperature is maintained -10° C to -15° C. Then circulation of brine is started in heat exchanger of condensation system. Addition of chlorine is also started through sparger at the temperature range of 20 - 55° C. Bromine liberated (separate out) from hydrobromic acid when pass the chlorine in hydrobromic acid. Bromine is condensed in condenser and collected. It is to be re-use for bromination. Unreacted chlorine is scrubbed in scrubber by caustic (NaOH) solution. In the third step, amonolysis, sodium bromide is generated. Bromine is recovered form this as per earlier describe. The yield of Br2 (Bromine) recovery is around 95 %. The invention is illustrated more in detail in the following examples. The examples describe and demonstrate embodiments within the scope of the present invention. These examples are given solely for the purpose of illustration and are not to be construed as limitations of the present invention, as many variations thereof are possible without departing from the spirit and scope. Followings are the Examples for preparation of 3, 5 dichloroaniline from dichloro benzene Raw Material Purity Step I 1. m - DichorobenzeneOR p- DichlorobenzeneOR Mixture of m-Dichlorobenzene + p- Dichlorobenzene Min. 99.5 %Min. 99.5 %50 -70 % 30 - 50 % 2. Bromine 99% 3. Aluminum chloride/Ferric chloride 97 to 99 % Step II 4. Dichlorobromobenzene Min. 95-99 % 5. Aluminum chloride 98 to 99 % Step III 6. 3,5 Dichloro bromo benzene 99% 7. Cuprous chloride/Cuprous oxide 97 to 99 % 8. Liquid ammonia Concentration : Min. 20 % in water (w/w) 9. Solvent Min 99 % Detail desription of examples as per following tables : Step - 01 : Formation of Dichloro Bromo Benzene from Dichloro Benzene. Consider following abbreviation. DCB - Dichloro benzene. DCBB - Dichloro brome benzene. DCDBB - Dichloro dibromo benzene. ExampleNo Raw material Temp °C Results Name Qty (gm) 01 (1)1,4 dichloro benzeneOR 1,3 dichloro benzeneOR Mixture of 1,3 dichloro benzene and 1,4 dichloro benzene. (II)Aluminium chloride/ Ferric chloride 1002-5 40 to 80 30-35 % DCB 60-65 % DCBB 02 -05 % DCDBB (III)Bromine 65 02 (1)1,4 dichloro benzeneOR1,3 dichloro benzeneOR Mixture of 1,3 dichloro benzene and 1,4 dichloro benzene. (II)Aluminium chloride/ Ferric chloride (III)Bromine 1002-5 65 30 to 60 30-35 % DCB 60-65 % DCBB 02 -05 % DCDBB 03 (1)1,4 dichloro benzeneOR 1,3 Dichloro benzeneOR Mixture of 1,3 dichloro benzene and 1,4 100 10 to 40 30-35 % DCB 50-65 % DCBB 05 -10 % DCDBB dichloro benzene. (II)Aluminium chloride/ Ferric chloride (III)Bromine 2-5 65 Step - 02 Isomerisation of Dichloro Bromo Benzene Concider following abbreviation Catalyst: Aluminium Chloride DCBB : Dichloro bromo benzene ExampleNo Raw material Temp°C Catalyst Qty (gm) Results Name Qty(gin) 01 Dichloro bromo benzene 100 110-180 30 Found 30-50 % conversion into 3,5 DCBB 02 Dichloro bromo 100 130- 30 Found 40-50 % benzene 220 conversion into 3,5 DCBB 03 Dichloro bromo 100 110- 40 Found 30-50 % benzene 180 conversion into DCBB 3,5 04 Dichloro Bromo 100 130- 40 Found 30-40 % Benzene 220 conversion into DCBB 3,5 Step -03 Amonolysis Consider following abbreviation DCBB : Dichloro bromo benzene. CDAB : Chloro diamino benzene. Temp: Temperature. Press : Pressure. Cat: Catalyst.(Cuprous chloride/ Cuprous Oxide) Exa mpleNo Raw material Condition Results 3,5 DCBB (gms) Ammonia (gms) Cat (gms) Temp °C Press kg/cm2 01 100 2500 0.5 130-250 10-60 Found the good conversion in to 3,5 DCA 02 100 2500 0.5 130-250 15-80 Found the conversion in to 3,5 DCA but found CDAB around 1-5 % 03 100 2500 1.0 130-250 10-60 Found the good conversion in to 3,5 DCA 04 100 2500 1.0 130-250 15-80 Found the conversion in to 3,5 DCA but found CDAB around 1-5% I Claim: 1. The process for preparation of 3, 5 dichloroaniline comprising: I - Formation of dichloro bromo benzene from dichloro benzene: (a) taking m-dichloro benzene or p-dichloro benzene or mixture of m-dichloro benzene and p-dichloro benzene, aluminium chloride/ferric chloride in glass flask and slowly adding bromine; (b) stirring and then scrubbing HBr gas; (c) stirring the mixture obtained in step (b) for half an hour, II - Isomerization of dichloro bromo benzene: (d) mixing dichloro bromo benzene and aluminum chloride and heating; (e) cooling down up to room temperature; (f) optionally distillating and crytalizing 3, 5 dichloro bromo benzene before next step; III - Amonolysis : (g) charging 3,5 dichloro bromo benzene with cuprous chloride / cuprous oxide and ammonia solution in water; (h) heating at 130 - 250° C at 10 -60 kg/cm2 pressure for 2 ½ - 10 hours; (i) cooling down up to 80 - 100° C and recovering ammonia gas; (j) Further cooling down up to 35 - 40° C; (k) adding NaOH and heating at 80 - 90° C to recover the ammonia from ammonium bromide; (1) cooling down up to 30 - 35° C for one hour; (m) adding solvent, stirring and allowing to settle down; (n) separating solvent layer and aqueous layer and filtering; (o) distillating and crystallizing. 2. A process as claimed in claim 1 step (a) wherein temperature is 10 - 50 ° C. 3. A process as claimed in claim 2 wherein more preferably temperature is 20 -50 °C. 4. A process as claimed in claim 1 step (d) wherein mixture is heated for 130 -220 °C for 4 hours. 5. A process as claimed in claim 4 wherein more preferably heating is done for 130-200° C. 6. A process as claimed in claim 1 step (d) wherein 40- 50 gm aluminum chloride is used. 7. A process as claimed in claim 1 step (m) where in solvents are selected from the group of propanol, butanol, pentanol, ethyl acetate, toluene, o-dichloro benzene, butyl acetate, n-ethyl diisopropyl amine. 8. A process as claimed in claim 1 step (k) where in 7-8 gm NaOH is used. 9. A process as claimed in claim 1 wherein bromine is separated out from hydrobromic acid by addition of chlorine. 10. A process is claimed in claim 1 step (k) where in bromine is separated out from sodium bromide by addition of chlorine. 11. The process for preparation of 3, 5 dichloroaniline substantially as described herein before and with reference to the foregoing examples. ABSTRACT The present invention disclosed process for preparation of 3, 5 dichloroaniline. A process for producing 3, 5 dichloroaniline comprising (a) bromination of dichloro benzene or mixed dichloro benzene to produce dichloro bromo benzene (b) isomerization of dichloro bromo benzene and separation of 3, 5 dichloro bromo benzene and (c) amonolysis of 3, 5 dichloro bromo benzene to produce 3, 5 dichloroaniline. 90 to 94% bromine is recovered from 42 to 48% hydrobromic acid and sodium bromide. Production of 3, 5 dichloroaniline is at very low cost and without creating much pollution.

Documents:

1890-mum-2007-abstract(27-9-2007).doc

1890-mum-2007-abstract(27-9-2007).pdf

1890-mum-2007-abstract.doc

1890-mum-2007-abstract.pdf

1890-mum-2007-claims(granted)-(27-9-2007).doc

1890-mum-2007-claims(granted)-(27-9-2007).pdf

1890-mum-2007-claims.doc

1890-mum-2007-claims.pdf

1890-mum-2007-correspondence(22-11-2007).pdf

1890-mum-2007-correspondence(ipo)-(20-2-2009).pdf

1890-mum-2007-correspondence-received.pdf

1890-mum-2007-description (complete).pdf

1890-mum-2007-form 1(27-9-2007).pdf

1890-mum-2007-form 18(26-11-2007).pdf

1890-mum-2007-form 2(granted)-(27-9-2007).doc

1890-mum-2007-form 2(granted)-(27-9-2007).pdf

1890-mum-2007-form 26(27-9-2006).pdf

1890-mum-2007-form 3(27-9-2007).pdf

1890-mum-2007-form 5(27-9-2007).pdf

1890-mum-2007-form 9(3-10-2007).pdf

1890-mum-2007-form-1.pdf

1890-mum-2007-form-2.doc

1890-mum-2007-form-2.pdf

1890-mum-2007-form-26.pdf

1890-mum-2007-form-3.pdf

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