Title of Invention

AN IMPROVED PROCESS FOR THE PRODUCTION OF HYDROXY PHENYL KETONES

Abstract An improved process for the production of hydroxy phenyl ketones of formula wherein R=-COCH2CH3 or -COC6H5, which comprises acylating, with an acylating agent in the presence of a solid crystalline microporous catalyst composite material Consisting of alumino-silicate having molar composition in anhydrous state as follows: M/n:AlO2:zSiO2(where M is proton or alkali or alkaline or rare earth metals with valency n and z is between 2-500) having SiO2/Al2O3 molar ratio of from 2-50 and a pore size of 5-10 Adeg. at a temperature in the range 100 to 240deg. C, for 0.5 h to 20 h and separating the product by conventional methods to obtain the product.
Full Text The present invention relates to an improved process for the production of hydroxy phenyl ketones. More particularly it relates to the said process for preparation of hydroxy phenyl ketones having formula (I)
r
o
Formula -1
Where in R = -COCH2CH3 or -COC6H5 using phenol.
Ketones are used mainly as a photoinitiator for special printing plates, as well as for organic synthesis. Hydroxy phenyl ketones are also used for hawthorm, type perfumes, especially in soap perfumes.
In the prior art, an acyl group is introduced in the aromatic nucleus by an acylating agent such as an acyl halide, acid anhydride or acid itself in the presence of homogenous catalyst such as AlCl3 or BF3 (Encyclopedia of chemical Technology, VolD, page 1055, 1944)
Other process includes Friedel crafts acylation of various aromatics with a wide variety of acylating agents and metal halides such as AlBr3, FeCl3 FeBr3, SbBr3j, SbBr3, TiCL4, CbCl5, NbCl5, GaCl3 and ZrCL4. Some of these may give yeilds comparable to those obtained with AlCl3 (Friedel Crafts and Related reaction, VolII, Part, 1964, Ed. GA. .Olah)
Ortho- and para- acylated products of phenol have been made from the direct reaction of phenol with acylating agent or by the Fries rearrangement of aryl esters using Lewis acid catalyst, AlCl3 (Ullamans Encyclopedia Vol. Al, p. 209;

Liebigs.Ann.Chem. 460 (1928) 56; Kokai Tokkyo Koho JP 01071835 (1989); BF3 (Ger.Offen. DE 3831092 (1990).
In one method propionylation of phenol with propionic acid was carried out using ZnCl2 which consist of 12% yield of 4-HPP (4-Hdroxypropiophenone) (Friedel carft Related reaction Vol III 1964, p. 168, Ed G.A.Olah).
A method comparising reacting phenol with propionyl chloride in the presence of A1C13 gives 65% yield of 4-HPP ( Friedel carft Related reaction Vol III 1964, p. 168, Ed G.A.01ah)
Other process includes the preparation of hydroxybenzophenones (4-HBP) by the benzolylation of phenol with aromatic carboxylic acid using strongly acidic ion-exchangers as catalyst (Jpn. Kokai Tokkyo Koho JP 61282335 (1986).
There have been known a number of methods for preparing hydroxy phenyl ketones by reacting phenol with propionylchloride and benzoic anhydride respectively using Lewis acid catalysts. However the above methods are disadvantageous from the industrial point of view because of low selectivity for 4-HPP and 4-HBP and the catalyst used are homogeneous. Thus the large amount of base is required to neutralise the homogeneous catalysts.
The chemical industries are facing increasing pressure to reduce its impact on environment. This is particularly true in the production of hydroxy phenyl ketones. Such reactions often require large quantities of minerals or Lewis acid catalysts which are destroyed or diluted during the aqueous work-up procedures, leadings to problems with equipment corrosion and expensive to treat. Furthermore, the reactions frequently use excess of reagents and are notoriously unselective. The overall result is excessive energy consumption, wastage of large quantities of Lewis acid catalysts and

homogeneous Lewis acid catalysts is the difficulty of their disposal, after use in the propionylation and benzoylation reactions of phenol, in an environmentally acceptable manner.
1. In view of the above mentioned drawbacks of homogeneous catalysts in the prior art process, it was found desirable during the course of the research work leading to the present invention to develop an environmentally acceptable solid selective, regenerable and recyclable zeolite catalysts for the production of hydroxy phenyl ketones and particularly 4-HPP and 4-HBP in high selectivity from the acylation ( propionylation and benzoylation ) of phenol with propionyl chloride and benzoic anhydride, respectively in the presence of solid aicd catalyst composite materials alumino-silicate zeolite catalyst.
2. The AlCl3 catalyst cannot be used with a number of hetrocyclic system which are decomposed by it due to its higher Lewis acid strength.
3. The use of AlCl3 may give rise to some side reaction of intra-or intermolecular.
4. Migration of alkyl groups, acylation and replacement of halogen atoms.
5. Difficult operational problem of corrosion.
6. Difficulty in the catalyst (AlCl3) or HC1 removal from the products.
7. Use of stoichiometric amount of catalyst in all the methods described above.
Some of them are hazardous and difficult to handle. In some cases catalyst is consumed during the reaction and in some cases catalyst are less active.
It is therefore an object of the present invention to provide an improved process for the production of hydroxy phenyl ketones by the acylation (propionylation and benzoylation) of phenol in the presence of zeolite catalyst.

Another object of the present invention is to obviate the drawbacks and limitations of the prior art such as removal of HC1 from the product form during the reaction, use of AlCl3 give rise to many side chain reaction.
Still another object of the present invention is to provide an improved process which makes use of non-hazardous solid zeolite catalyst.
A further object of the present invention is to provide an improved process which leads to high yields of ketones and selectivity to para products resulting from high conversion of phenol.
Still another object of the invention is to provide an improved process which is safe not being prone to explosion.
It has been found that the object of the present invention can be obtained by using microporous aluminosilicate zeolites as catalyst. In accordance with the process of the present invention phenol can be converted to 2-hydroxypropiophenone, 4-hydroxypropiophenone, 2-hydroxybenzophenone and 4-hydroxybenzophenone in the presence of a zeolite catalyst composite material aluminosilicate using solution of an acylating agent and phenol with stirring in a batch reactor, such zeolites may be usually sodium or potassium but may further include other cations such as rare earth metals. The cations may be of the same type or of two or more different types.
Formula -1
Accordingly, the present invention provides an improved process for the production of hydroxy phenyl ketones of formula (1)


Where in R = —COCH2CH3 or—COC6H5, which comprises acylating phenol with an acylating agent in the presence of a solid crystalline microporous catalyst composite material alumino silicate at a temperature in the range 100 to 240° C, for 0.5 h to 20 h and separating the product by conventional methods like gas-chromatography to obtain the product.
In one of the embodiment of the present invention, the acylating agent is selected from the propionic or benzoic acids or their anhydrides or chlorides.
In yet another embodiment of this invention the zeolite catalyst used in the reaction is selected from H-ZSM-5 or H-beta or H-mordenite or faujasite, having molar composition in anhydrous state as follows:
M/n : A1O2: zSiO2
(Where M is proton or alkali or alkaline or rare earth metals with valency n, and z is between 2-500) having SiO2/Al2O3 molar ratio of from 2-50 and a pore size of 5-10 A0.
In another embodiment of this invention the molar ratio of phenol to acylating agents may be from 1:1 to 20:1.
In a feature of the present invention the process it is possible to selectively and efficiently acylate the para-position of the substrate while suppressing the acylation at the ortho and meta position.
The present invention is described in a further detail with reference to the following examples, which should not be however construed to limit the present invention in any manner whatsoever.

EXAMPLE 1
This example illustrates the procedure for the benzoylation of phenol to 4-hydroxybenzophenone, 2-hydroxybenzopenone and phenylbenzoate. 20 g of phenol and 3 g benzoic anhydride were taken in an Parr autoclave. 0.5 g of catalyst composite material zeolite H-beta was added to the reaction mixture. The reaction mixture was heated up to 110° C with stirring. The reaction was continued for 18h. The reaction mixture was cooled down to room temperature and analysed with gas chromatograph. The results are recorded in Table 1. TABLE 1 : Benzoylation of phenol with benzoic anhydride over catalyst composite
materials alumino-silicates zeolite H-Beta after 18h.

Conversion of benzoic anhydride (wt%) 95.3%
Product distribution (wt%)
4-Hydroxybenzophenone (4-HBP) 24.4
2-Hydroxybenzophenone (2-HBP) 11.4
Phenylbenzoate 64.2
4-HBP/2-HBP 2.14
EXAMPLE 2
This example illustrate the procedure for the benzoylation of phenol to 4-hydroxybenzophenone, 2-hydroxybenzophenone and phenylbenzoate. 30 g of phenol and 4 g of benzoic anhydride were taken in an Parr autoclave. 1 g of catalyst composite material zeolite H-beta was added to reaction mixture. The reaction mixture was heated up to 240° C with stirring and the reaction was continued for 20 h the reaction mixture was cool down to room temperature and the products are

TABLE 2 : Benzoylation of phenol with benzoic anhydride over catalyst composite materials alumino-silicates zeolite H-beta after 20 h.

Conversion of benzoic anhydride (wt%) 95.3
Product distribution (wt%)
4-hydroxybenzophenone 24.4
2-hydroxybenzophenone 11.4
Phenylbenzote 64.2
4-HBP/2-HBP 2.1
EXAMPLE 3
This example illustrates the procedure for the benzoylation of phenol to 4-Hydroxybenzophenone, 2-Hydroxybenzophenone and phenylbezoate. 30 g of phenol and 2 g benzoic anhydride were taken in an Parr autoclave. 0.7 g of catalyst composite material zeolite H-Y was added to the reaction mixture. The reaction mixture was heated upto l0h and cooled down to room temperature and analyzed by gas chromatograph. The results are recorded in Table 3. TABLE 3 : Benzoylation of phenol with benzoic anhydride over catalyst composite
materials alumino-silicates zeolite H-Y after l0h.

Conversion of benzoic anhydride (wt%) 96.2
Product distribution (wt%)
4-Hydroxybenzophenone 16.9
2-Hydroxybenzophenone 25.7
Phenylbenzoate 57.2
4-HBP/2-HBP 0.66

EXAMPLE 4
This example illustrates the procedure for the benzoylation of phenol to 4-hydroxybenzophenone, 2-hydroxybenzophenone and phenylbenzoate. 15 g of phenol and 1.5 g benzoic anhydride were taken in an Parr autoclave. 1 g catalyst composite material zeolite RE-Y was added to the reaction mixture. The reaction mixture was heated up to 120°C with stirring for 18h .The reaction mixture was cooled down and analyzed with gas chromatograph.The results are recorded in Table 4. TABLE 4 : Benzoylation of phenol with benzoic anhydride over catalyst composite
materials alumino-silicates zeolite RE-Y after 18h.

Conversion of benzoic anhydride (wt%) 93.1
Product distribution (wt%)
4-Hydroxybenzophenone 16.5
2-Hydroxybenzophenone 16.5
Phenylbenzoate 60.7
4-HBP/2-HBP 1
EXAMPLE 5
This example illustrates the procedure for the propionylation of phenol to 4-hydroxypropiophenone, 2-hydroxypropiophenone and phenyl propionate. 35 g of phenol and 1.3 g propionyl chloride were taken in an batch reactor. 0.2 g catalyst composite material zeolite H-beta was added to the reaction mixture. The reaction mixture was heated up to 100°C with stirring for 6 h .The reaction mixture was cooled down and analyzed with gas chromatograph. The results are recorded in Table 5.

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EXAMPLE 7
This example illustrates the procedure for the propionylation of phenol to 4-hydroxypropiophenone, 2-hydroxypropiophenone and phenyl propionate. 20 g of phenol and 1.5 g propionyl chloride were taken in an batch reactor. 0.4g catalyst composite material zeolite H-Y was added to the reaction mixture. The reaction mixture was heated up to 120°C with stirring for 6 h .The reaction mixture was cooled down and analyzed with gas chromatograph. The results are recorded in Table 7. TABLE 7 : Propionylation of phenol with propionyl chloride over catalyst composite
materials alumino-silicates zeolite H-ZSM-5 after 6 h.

Conversion of phenol (wt%) 31.3
Product distribution (wt%)
4-Hydroxypropiophenone (4-HPP) 4.6
2-Hydroxypropiophenone (2-HPP) 1.2
Phenyl propionate 94.2
4-HPP/2-HPP 3.8
EXAMPLE 8
This example illustrates the procedure for the propionylation of phenol to 4-hydroxypropiophenone, 2-hydroxypropiophenone and phenyl propionate and others. 50 g of phenol and 1.7 g propionyl chloride were taken in an batch reactor. 0.8 g catalyst composite material zeolite RE-Y was added to the reaction mixture. The reaction mixture was heated up to 140°C with stirring for 6 h .The reaction mixture was cooled down and analyzed with gas chromatograph. The results are recorded in Table 8.

materials alumino-silicates zeolite RE-Y after 6 h.

Conversion of phenol (wt%) 30.4
Product distribution (wt%)
4-hydroxypropiophenone (4-HPP) 4.9
2-hydroxypropiophenone (2-HPP) 3.7
Phenyl propionate 91.0
4-HPP/2-HPP 1.3
EXAMPLE 9
This example illustrates the procedure for the propionylation of phenol to 4-hydroxypropiophenone, 2-hydroxypropiophenone and phenyl propionate. 20 g of phenol and 1.7 g propionyl chloride were taken in an batch reactor. 1.5 g catalyst composite material zeolite H-mordenite was added to the reaction mixture. The reaction mixture was heated up to 90°C with stirring for 6 h .The reaction mixture was cooled down and analyzed with gas chromatograph. The results are recorded in Table 9. TABLE 9 : Propionylation of phenol with propionyl chloride over catalyst composite
materials alumino-silicates zeolite H-mordenite after 6 h.

Conversion of phenol (wt%) 34.0
Product distribution (wt%)
4-hydroxypropiophenone (4-HPP) 3.3
2-hydroxypropiophenone (2-HPP) 5.1
Phenyl propionate 90.1
4-HPP/2-HPP 0.6

EXAMPLE 10
This example illustrate the effect of reaction time on the conversion of phenol to 4-HPP, 2-HPP and phenylpropionate in the propionylation of phenol. 15 g of phenol and 0.5 g propionyl chloride were taken in the batch reactor. 0.75 g catalyst composite material zeolite H-beta was added to the reaction mixture. The reaction mixture was heated up to 140° C and sample were taken at different time interval up to 6 h. The product samples were analysed by gas chromatograph. The results are reported in the Table 10.
TABLE 10 : Propionylation of phenol with propionylchloride over catalyst composite material alumino-silicates zeolite H-beta at different reaction time.

Reaction time (h) 0.5 1 2 4 6
Conversion of phenol (wt%) 35.3 33.7 33.5 33.7 34.5
Product distribution (wt%)
4-Hydroxypropiophenone 1.3 2.9 7.2 12.1 19.1
2-Hydroxypropiophenone 1.5 3.2 6.7 8.9 6.8
Phenylpropionate 97.2 93.7 85.5 78.9 74.8
4-HPP/2-HPP 0.9 0.9 1.1 1.4 2.8
The process of present invention shows remarkably high industrial merits over prior art process for the preparation 4-hdroxybenzophenone and 4-hydroxy-

The starting materials are easily available and easy to handle and that ketone can be produced in high yield by extremely simple operation.
Yet another advantageous feature of the process of the present invention is the use of the non-hazardous solid alumino silicate catalysts.
Another important and advantageous feature of the process of the present invention is that it does not pose risk of explosion. The most important and advantageous feature of the process of the invention is that both the yield and the selectivities to para substituted phenyl ketones are very high.
The use of zeolite as the catalyst in the liquid phase organic reaction of the present invention provides the following advantages:
1. Easy separation of the product from the solid by means of a simple procedure of filtration.
2. Adsorption or inclusion of substrate and reagent molecules into the small pores of solids with nanometer dimension organizes the molecules in close proximity to lower the activation energy of the reaction.
3. Well defined crystalline structure, uniform micro cavities effecting selective reactions of organic molecules incorporated therein under restriction.
4. High cation-exchangeability to ensure easy adjustment of their acidic and basic properties in a wide range of acidity.

Documents:

claims.pdf

correspondence-others.pdf

correspondence-po.pdf

description complete.pdf

form-1.pdf

form-18.pdf

form-2.pdf

form-3.pdf


Patent Number 216704
Indian Patent Application Number 122/DEL/2002
PG Journal Number 13/2008
Publication Date 28-Mar-2008
Grant Date 18-Mar-2008
Date of Filing 15-Feb-2002
Name of Patentee COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH.
Applicant Address RAFI MARG, NEW DELHI-110001, INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 VANDANA DHANANJAY CHAUBE CHEMICAL LABORATORY, PUNE 411008 MAHARASHTRA, INDIA.
2 ANAND PAL SINGH CHEMICAL LABORATORY, PUNE 411008 MAHARASHTRA, INDIA
PCT International Classification Number C07C 45/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA