3-A Patents Act, 1970 (See Section 10) Title:- A novel process for the preparation of
I) 2 - phenyl - 2 - propanol acetate [3425 - 72 - 7J as the main product and 2 - phenyl -
2 - propanol [617 - 94 - 71 from 2-phenyl-2-propene [98 - 83 - 9[.
II) 2-methyl-l-phenyl-2-propanol acetate [151-05-3] as the main product and 2-methyi-
l-phenyl-2-propanol [100-86-7] from mixture of 2-methyl-l-phenyl-l-propene [768-49-0] and 2-methyl-3-phenyl-l-propene.



The following specification particularly describes and ascertains the nature of the invention
and the manner in which it is to be performed.
1

The present invention relates to a novel process for the preparation of compounds of Formula I and IA( as described below) along with small amounts of compounds of Formula II and IIA, respectively (as described below) from compounds of Formula III and IIIA, respectively ( as described below), i) 2-phenyl-2-propanol acetate as the main product, and 2-phenyl-2-propanol:
2-phenyl-2-propanol acetate (Formula I) and 2-phenyl-2-propanol (Formula II), commonly known as phenyl dimethyl carbinyl acetate and phenyl dimethyl carbinol.

FORMULA (I) FORMULA (II)
ii) 2-methyl-I-phenyI-2-propanol acetate as the main product, and 2-methyl-l-phenyl-2-propanol.:
2-methyl-l-phenyl-2-propanol acetate (Formula IA) and 2-methyl-l-phenyl-2-propanol (Formula IIA), commonly known as dimethyl benzyl carbinyl acetate and dimethyl benzyl carbinol.

FORMULA (IA) FORMULA (IIA)
This invention particularly relates to a novel process for the preparation of compounds of Formula I and II from compounds of Formula III viz. 2-phenyl-2-propene and that for the preparation of compounds of formula IA and IIA from compound of Formula III A viz a


mixture of 2-methyl-l -phenyl- 1-propene and 2-methyl-3-phenyl-2-propene.

FORMULA (III)

FORMULA (IIIA)

The process of the present invention more particularly provides a novel method for the preparation of 2-phenyl-2-propanol acetate in yield ranging from 60 - 76 % and 2-phenyl-2-propanol in yield ranging from 20 - 40% and the conversion level ranging from 70 - 75% based on 2-phenyl-2-propene. The formation of by-products mainly dimers of the 2-phenyl propene, formed in the process due to the reaction conditions employed, are avoided.
And also the process of the present invention more particularly provides a no\ el method for the preparation of 2-methyl-1-phenyl-2-propanol acetate in the yield ranging from 55 - 85 % and 2-methyl-1-phenyl-2-propanol in the yield ranging from 15 - 45% and the conversion level of 20 - 25 % based on mixture of 2-methyl-l-phenyl-1-propene and 2-methyl-3-phenyl-2-propene, in 10 - 12 hr. The formation of by-products is completely avoided and the substantial improvement in the yield of acetate as compared to the existing processes is realised.
2-phenyl-2-propanol acetate and 2-phenyl-2-propanol are useful as important ingredients for perfumery and flavour formulations. 2-phenyl-2-propanol acetate has a floral fruity odour similar to that of skin of peach. 2-phenyl-2-propanol has a floral green odour similar to that of rose petals.
2-methyl-1-phenyl-2-propanol acetate and 2-methyl-l-phenyl-2-propanol are excellent perfume materials for Lilac, Narcissus, Jasmine and in certain types of Rose 2-methyl-l-phenyl-2-propanol acetate has fresh and powerful, floral-fruity, slightly herbaceous


odour of Jasmine-Lily type. 2-methyl-1 -phenyl-2-propanol has warm-herbaceous-floral, slightly animal odour, reminiscent of Lilac and Elderflowers with undertones of fresh cut wood.
I) Prior art for the preparation of 2 - phenyl - 2 - propanol acetate and 2 - phenyl - 2 -propanol:
While several methods are reported for the preparation of 2-phenyl-2-propanol acetate from 2-phenyl-2-propanol, none is used commercially, possibly due to the use of costly starting materials. The most widely reported process for the preparation of 2-phenyl 1-2-propanol acetate is esterification of 2-phenyl-2-propanol with acetic anhydride. Use of various catalysts have been reported using this process route . One such process has been described in Angew. Chem., 1973, 85(19). which employs tetrabutyl ammonium iodide with dimethyl sulphate in aqueous system. Although the process gives good yields of 2-phenyl-2-propanol acetate this process suffers from the following disadvantages:
1) The use of 2-phenyl-2-propanol as a starting material makes this process economically less attractive due to high manufacturing cost of the 2-phenyl-2-propanol.
2) The process requires 50 % NaOH with petroleum ether and dimethyl sulphate as a solvent which require acid neutralisation in the effluent.
3) The phase transfer catalyst, tetrabutyl ammonium iodide, is expensive and requires an efficient technique to separate and recycle it.
The above listed drawbacks were partially overcame by process of acylation of 2-phenyl-2-propanol with acetic anhydride and 4-[Dimethyl Amino]-Pyridine (DMAP) described in./. Org .Chem., 1984, 49(21). In this process, ketenes and diketenes are formed as intermediates which are difficult to handle on the large scale due to their hazardous nature. However, the main drawback of this process is the use of costly starting raw materials instead of alternate cheap raw materials such as 2-phenyl-2-propene which indeed is the main utility of the present invention.
4

Cobalt (II) Chloride catalysed acylation of 2-phenyl-2-propanol with anhydride in acetonitrile is reported in J. Chem. Soc.,Chem. Commun., 1987, (2). Although the yield of 2-phenyl-2-propanol acetate is reported to be high, the use of acetonitrile as a solvent, which is costly and difficult to handle, makes the process less attractive on the large scale. The high costs of cobalt (II) chloride, 2-phenyl-2-propanol, and anhydride is the main drawback of this process. However, this process overcomes the drawback of elimination of p-acetoxy carbonyl compound with DMAP catalyst.
The slightly modified form of above process has been reported in J . Org. ("hem., 1992,57(7). However, the main cause of concern of high cost of 2-phenyl-2-propanol and anhydride is remained untouched. Moreover, the reaction proceed via a tert. alkoxy radical and ketene in the presence of cobalt (II) chloride which is difficult to control and handle on the large scale due to their hazardous nature. The by-products like acetoacetates, olefins, and diketenes along with ketenes are observed in significant yield. Thus the separation of 2-phenyl-2-propanol acetate becomes a tedious task.
A method of acylation of 2-phenyl-2-propanol with acetic anhydride in the presence of DMAP is reported in Pol. J. Appl. Chem., 1993, 37(3-4). However, the drawbacks listed above makes this process economically unattractive on the large scale.
Enzyme, Lipase Saiken-100, catalysed acylation of alcohols with silylketenes in organic media is described in Chem. Express, 1993, 8(5). However, the lipase saiken-100 is costly and demands for the proper storage and efficient recovery process. The acylation was carried out with methylsilyl ketenes which are difficult to handle and are not readily available on large scale.
The main drawback of use of costly 2-phenyl-2-propanol (alcohol) for the acylation is overcame in a process which is reported in Indian J. Chem., Sect.B, 1993, 32B(4). The process makes use of dry hydrogen chloride gas to hydrochlorinate 2-phenyl-2-propene under anhydrous conditions and at low temperature of about 10 °C and 4 h, which on
5

nucleophillic substitution, under anhydrous conditions and at low temperature of about 10 -15 °C and 2 h, using zinc acetate of about 1:1 moles to that of hydrochlorinated olefin in 2 moles of glacial acetic acid gives 92% yield of 2-phenyl-2-propanol acetate. The process is attractive since the formation of 2-phenyl-2-propene dimers can be fully avoided.
However, the use of zinc hydroxide and zinc acetate is the main drawback of the process since zinc compounds are costly and requires efficient separation method.
The direct esterification of alkyl benzenes by KBrC>3 in the presence of cerium ammonium nitrate (CAN) is described in J. Mol. Catal. A : Chem., 1997, 116(3). However, the catalyst cost in this process is the main disadvantage among the others. For large scale operation the availability of KBr03 makes the process unattractive.
The treatment of 2-phenyl-2-propanol with acetic anhydride in the presence of chlorotrimethylsilane in acetonitrile (or dichloromethane) is reported in synth. Commun., 1997, 27(2). However, the drawbacks of this process are similar as mentioned earlier.
An efficient method for the acylation of alcohols with isopropenyl acetate by the use of an oxime esters and Cp2*Sm (thf)2 as a catalyst is described in J. Org. Chem.. 1997, 62(23). However, the use of costly isopropenyl acetate and the catalyst makes this process economically nonviable proposition on large scale. The availability of these compounds is again the major drawback.
The process patent, of reaction of oxime esters with alcohol in the presence of a metal
catalyst to give esters in high yields, has been filed in Japan Kokai Koho publication No.
1180, 078 (1999). This process efficiently converts alcohols into esters under neutral or near
neutral conditions. But the drawbacks are common as that for processes described above
In more recent European patent, No. 949, 239 (1999), acylation of alcohols with one or more hydroxy groups is reported. The alcohols are esterified with ketene in the presence of zinc carboxylate to give high yields of acetates. However, the method suffers from the high cost of alcohol, zinc carboxylates and that of ketene on large scale.
6

II) Prior art for the preparation of 2-methyl-1 -phenyl-2-propanol acetate and 2-methyl-1-phenyl-2-propanol:
2-methyl-1-phenyl-2-propanol is hitherto been prepared by Grignard reaction of organic halide and a ketone using Mg in the presence of cyclic and/or noncyclic ethers. Such a process has been described in Japanese Patent Kokai Publication no. 7430,333 (C1 16C45); appl. 7270,851 (1974).
In a Japanese Patent Kokai Publication No.5818, 323 (1983) the use of tetrahydrofuran-toluene has been reported for effecting the above said reaction. A problem in these processes is use of costly reagents like magnesium and ether or tetrahydrofuran. In addition to this problem, the process is also hazardous since the reagents such as magnesium halide, acetone etc. are highly reactive resulting in a possibility of explosions. Further the solvents used are highly flammable and the organic halides used are lachrymatory and corrosive. Moreover, the recovery and disposal problem of Magnesium hydroxide formed during the reaction in these processes makes them highly polluting.
It is known from German Patent no 2726064 (1977) that the reaction of organic halide, for example PhCH2CMe2O2CH. PhCH2CMe2O2CH when saponified with NaOH yields 2-methyl-1 -phenyl-2-propanol.
The above said process suffers from the disadvantages of high cost of raw materials, particularly of the desired organic halide. Also, the desired organic halide is not available easily on commercial scale. In addition the process leads to substantial generation of effluent through use of sulphuric acid and caustic soda. Further the use of halocarbon leads to inferior quality product from the point of its olfactory value despite a stringent separation procedure.
In view of these constraints the above process was modified to use an aromatic olefin as a reactant instead of the halide. Such a process has been described in Patent Publication HP 44,514 (1982). According to this process 2-methyl-l-phenyl-2-propanol was prepared by reaction of HCOOH with PhCH2CMe:CH2 in the presence of sulphuric acid and a C1-C10 alcohol.
Although this process overcomes the disadvantage of using a halide, it doesn't eliminate or minimise the other drawbacks mentioned for the former process i.e., high cost of effluent treatment.
An electrochemical process for the production of 2-methyl-l-phenyl-2-propanol is also known and is described in French Patent Publication No. FR 2,579,627 (1986) In this process electrochemical reduction of organic halide in presence of carbonyl compound in an
7

organic solvent medium containing an inert electrolyte, using a cell having an anode made of Mg. Al, Zn or their alloys gives alcohol i.e., 2,methyl-l-phenyl-2-propanol.
The disadvantages of this process are the same as those earlier enlisted. The problems due to use of halide persist although the process is simple and suitable for large scale operation. Further the cost of consumable anode and electrolyte makes the process expensive.
In order to avoid the use of halocarbons the use of benzylic derivatives chosen from benzylic quaternary ammonium or phosphonium salts, benzylic sulphonium or thiocynate or alcohol ester compounds has been reported in the French Patent No. FR 2,632,978 (1989). Although this process avoids the use of halide, the alternate reactants used are expensive and are not readily available on large scale.
Though various processes are known in the art for producing 2-methyl-l-phenyl-2-propanol, these processes suffer from various disadvantages which make them less attractive for the commercial application.
Oxidation of Isobutyl Benzene is known to give a mixture of 2-methyl-1 -phenyl
hydroperoxide and 2-methyl-1-phenyl-2-propyl hydroperoxide along with substantial quantities of 2-methyl-1-phenyl-1-propanone. Such a process has been reported in a Polish publication viz. Chem. Stosow., 1988, 32 (3-4) ; 5230-33 (Polish).
Though various processes has been reported in the art of producing the compounds of Formula 1/ IA and 11/ IIA from the compounds of Formula III/ IIIA, these processes suffer from various disadvantages which makes them less attractive for the commercial application.
There is a possibility of a good market for 2-phenyl-2-propanol acetate and a substantial market already exists for 2-methyl-1-phenyl-2-propanol acetate in India and internationally due to their odour profile. It is therefore desirable to develop a process for the preparation of 2-phenyl-2-propanol acetate and 2-methyl-l-phenyl-2-propanol acetate on a commercial scale and in improved yield. Such a process should also overcome the problems which are being faced in the hitherto known processes.
Therefore the main objective of the present invention is to provide a novel process for the preparation of the compounds of Formula I and II from the compounds of Formula III
8

instead of from compounds of Formula II and also provide a novel process for the preparation of the compounds of Formula 1A and I1A from the compounds of Formula 111 V instead of from compounds of Formula IIA and as is the case for number of processes reported in the literature.
Yet another objective of the present invention is to make use of cheap and abundantly available sodium acetate and acetic acid, for the preparation of these acetates and carbinols from their respective olefins instead of zinc acetate and acetic acid.
Still another objective of the present invention is to make use of phase transfer catalyst to carry out the acylation with sodium acetate alone instead of zinc acetate and acetic acid.
Still another objective of the present invention is co-production of compounds of Formula II and IIA which are important perfumery materials.
Finally one of the objectives of the present invention is to provide a novel process for the preparation of these acetates and carbinols from their respective olefins which are simple and environmentally safe on commercial scale.
Accordingly, the present invention provides a novel process for the preparation of 2-phenyl-2-propanol acetate of formula I and 2-methyl-1-phenyl-2-propanol acetate of formula 1A from 2-phenyl-2-propene of formula III and mixture of 2-methyl-1-phenyl-1-propene and 2-methyl-3-phenyl-2-propene of formula IIIA, respectively which comprises
(i) Hydrochlorination of 2-phenyl-2-propene or mixture of 2-methyl-1-phenyl-1-propene and 2-methyl-3-phenyl-2-propene of the formulae III and IIIA respectively by dry hydrogen chloride gas, obtained from either 35 % hydrochloric acid or sodium chloride with 98 % sulphuric acid, at a temperature in the range of 10 - 15 °C, maintaining the anhydrous condition, at atmospheric or slightly above the atmospheric pressure, maintaining the controlled flow of dry hydrogen chloride, with constant speed of stirring of 1000 rpm to yield a mixture containing about 90 - 98 % 2-chloro-2-phenyl propane or 2-chloro-2-methyl-
9

1-phenyl-2-propane and 2 - 10 % 2-phenyl-2-propene or mixture of 2-methyl-1-phenyl- -propene and 2-methyl-3-phenyl-2-propene in 5 - 6 h. This mixture is then stored at about 20 - 25 °C for 24 h. The mixture was then neutralised with anhydrous potassium carbonate of about 30 weight % of reaction mixture. The solids were then separated with the vacuum filtration.
(ii) The 2-chloro-2-phenyl propane thus formed in step (i) is then reacted with anhydrous sodium acetate at the temperature range of 20 - 25 °C with the molar ratio of 2-chloro-2-phenyl propane to sodium acetate as 1 : 1.5 to 1 : 2 with glacial acetic acid of 5 mole % of 2-chloro-2-phenyl propane, with constant speed of stirring of 1000 rpm for about 2 - 3 h to give a mixture of 2-phenyl-2-propanol acetate, 2-phenyl-2-propanol, and 2-phenyl propene.
However, when 2-chloro-2-phenyl propane or 2-chloro-2-methyl-l-phenyl-2-propane is reacted with anhydrous sodium acetate with the molar ratio of 2-chloro-2-phenyl propane or 2-chloro-2-methyl-l-phenyl-2-propane to sodium acetate as 1 : 2 - 1 : 3, in the presence of tetrabutyl ammonium bromide as a phase transfer catalyst (in glacial acetic acid for 2-chloro-2-methyl-1-phenyl-2-propane only, with molar ratio of 2-chloro-2-methyl-l-phenyl-2-propane to acetic acid as 1 : 5 ) with the weight ratio of 2-chloro-2-phenyl propane or 2-chloro 2-methyl-l-phenyl-2-propane to phase transfer catalyst of 1 : 5, at about 40 - 70 °C, for 10 - 12 h, with the constant speed of stirring of about 1000 rpm, the reaction mixture contains 2-phenyl-2-propanol acetate or 2-methyl-3-phenyl-2-propanol acetate, 2-phenyl-2-propanol or 2-methyl-1-phenyl-2-propanol, and 2-phenyl-2-propene or 2-methyl-l-phenyl-2-propene. In these processes the other by-products as mentioned earlier are absent.
(iii) Separating the solids, sodium acetate and sodium chloride, from the acylation reaction mass; removing acetic acid by vacuum distillation at 25 - 30 °C, and washing the organic phase with water till neutral to give the product acetate.
(iv) Separating the compounds of Formula III (or IIIA), starting materials, from those
10

of Formulae I and II ( or IA and IIA) by distillation [ under vacuum ] at 0.1 to 2 mm Hg.
The present invention is based on our findings that if a dry hydrogen chloride gas, generated from 98 % sulphuric acid and 35 % hydrochloric acid or sodium chloride, when passed, in a controlled manner, through a reactor containing 2-phenyl-2-propene or mixture of 2-methyl-l-phenyl- 1-propene and 2-methyl-3-phenyl-2-propene (olefins) at 10 - 15 lC for 6 h, the formation of the dimers of olefins and other by-products can be avoided. Furthermore, the yield of 2-chloro-2-phenyl propane or 2-chloro-2-methyl-l-phenyl-2-propane of formulae IV and IVA respectively is increased.

FORMULA (IV) FORMULA (IVA)
When 2-chloro-2-phenyl-propane is treated with anhydrous sodium acetate in glacial acetic acid at 20 - 25 °C for 2 - 3 h gives the better yield of 2-phenyl-2-propanol acetate Furthermore from our findings if the phase transfer catalyst is used along with fused sodium acetate or anhydrous sodium acetate with minimal water content, the use of glacial acetic acid can also be avoided.
When 2-chloro-2-methyl-l-phenyl-2-propane is treated with sodium acetate and tetra butyl ammonium bromide as a catalyst in glacial acetic acid at 50 -70 °C for 10 -12h gives the better yield of 2-methyl-l-phenyl-2-propanol acetate. Only the yield of 2-phenyl-2-propanol or 2-methyl-l-phenyl-2-propanol formed, as a result of minimal water required for the phase transfer catalyst to impart its action, and the decomposition of 2-chloro-2-phenyl propane are marginally higher as compared to that in the presence of glacial acetic acid. However, the other by-products as mentioned above in the prior art in the conventional/ reported processes can be completely avoided.
11

By carrying out the reaction in the manner explained above the following advantages are availed :
(i) The use of cheaper compounds of Formula III and IIIAas compared to the costly compounds of formula II and IIAas a starting material.
(ii) The use of Narcotic controlled acetic anhydride for acylation can be avoided, (iii) The phase transfer catalyst can be used to avoid the use of acetic acid in case of 2-phenyl-2-propanol acetate.
(iv) There are no by-products leading to easier purification of compounds of Formula I and IA .
The process is described in detail in the Examples given below which are provided by way of illustration only and shouldn't be construed to limit the scope of the present invention.
EXAMPLE -1 (i) Hydrochlorination of compounds of Formula III with dry hydrogen chloride gas ;
2 kg of compounds of Formula III was reacted with dry hydrogen chloride gas in the molar ratio of 1:1 in a mechanically agitated glass reactor, with a dia of 15 cm and a height of 20 cm having a gas bubbler dip tube. Hydrochlorination of compounds of Formula III by dry hydrogen chloride gas obtained from 35 % hydrochloric acid dehydration with 98 % sulphuric acid at a temperature in the range of 10 - 15 °C, maintaining the anhydrous condition, at atmospheric or slightly above the atmospheric pressure, maintaining the controlled flow of dry hydrogen chloride with constant speed of stirring of 1000 rpm, to yield a mixture containing about 90 - 98 % of 2-chloro compounds of Formula IV in the reaction mixture in 5 - 6 h. This mixture is then stored at about 20 - 25 °C for 24 h. The mixture was then neutralised with anhydrous potassium carbonate. The solids were then separated with the vacuum filtration. The reaction mixture is then analysed on gas chromatography and the results are given in Table No. 1.


TABLE NO. 1
COMPONENT Weight % by GLC
2-phenyl-2-propene 9.80
2-chloro-2-phenyl-2-propane 90.20
Thus the yield of compounds of Formula IV, was 99 % at a conversion level of 90. (ii) Acvlation of compounds of Formula IV with sodium acetate :
In the second step, the mixture of 90 % 2-chloro-2-phenyl propane and 10 % 2-phenyl-2-propene was then taken in a mechanically agitated glass reactor of 15 cm dia and 15 cm height. First, anhydrous sodium acetate is suspended in glacial acetic acid, with the molar ratio of 2-chloro-2-phenyl-2-propane to anhydrous sodium acetate as 1 : 2, with continuous stirring at the speed of 1000 rpm. The heat of dissolution is removed with the help of cooling water at 20 °C. This mixture is allowed to cool upto 20 °C. Then stoichiometric amount of 2-chloro-2-phenyl propane is added dropwise to this mixture maintaining the temperature at about 20 - 25 °C and stirring continuously for about 2 - 3 h.
The reaction mixture is then filtered using vacuum for the recovery of sodium acetate and sodium chloride. The filtrate is then flashed to remove acetic acid under vacuum keeping the base temperature about 25 - 30 ° C. The remaining mixture is then washed with water until the pH of the mixture approaches near neutral condition.
The reaction mixture is then analysed on gas chromatography. The results are given in
Table No. 2.
TABLE NO. 2

COMPONENT Weight % by GLC
2-phenyl-2-propene 25.60
2-phenyl-2-propanoI 16.25
2-phenyl-2-propanol acetate 58.15
The reaction mixture is then taken for the distillation in a distillation unit with the height of packing 2.8 m and column diameter of about 5 cm. The distillation was carried out under constant vacuum of about 0.01 mm Hg. The first cut was collected at 10 -25 °C which mainly comprises of compounds of Formula III. In the second cut, compound of Formula II was


collected at 45 - 50 °C. After that, mid cuts were collected at 52 - 58 °C which comprise of compounds of Formulae I and II. Finally compound of Formula I was collected at about 60 -80 °C and 0.01 mm Hg. The overall recovery of compound of Formula I in this step is 98%.
The overall yield of 2-phenyl-2-propanol acetate based on 2-phenyl-2-propene obtained is about 76.6 % at a overall conversion level of 74.4 % of 2-phenyl propene The yield of 2-phenyl-2-propanol based on 2-phenyl-2-propene is about 21.4 %. Thus the combined overall yield of 2-phenyl-2-propanol acetate and 2-phenyl-2-propanol is 98 0 %
EXAMPLE - II (0 Hydrochlorination of compounds of Formula III A with dry hydrogen chloride gas :
2 kg of compounds of Formula IIIA was reacted with dry hydrogen chloride gas in
the molar ratio of 1:1 in a mechanically agitated glass reactor, with a dia of 15 cm and a
height of 20 cm having a gas bubbler dip tube. Hydrochlorination of compounds of Formula
IIIA by dry hydrogen chloride gas obtained from 35 % hydrochloric acid dehydration with
98 % sulphuric acid at a temperature in the range of 10 - 15 °C, maintaining the anhydrous
condition, at atmospheric or slightly above the atmospheric pressure, maintaining the
controlled flow of dry hydrogen chloride with constant speed of stirring of 1000 rpm, to
yield a mixture containing about 90 - 98 % of 2-chloro compounds of Formula IVA in the
reaction mixture in 5 - 6 h. This mixture is then stored at about 20 - 25 °C for 24 h The
mixture was then neutralised with anhydrous potassium carbonate. The solids were then
separated with the vacuum filtration. The reaction mixture is then analysed on gas
chromatography and the results are given in Table No. 3.
TABLE NO. 3
COMPONENT Weight % by GLC
2-methyl-l-phenyl-2-propene 0.3
2-methyl-3-phenyl-2-propene 4.5
2-chloro-2-methyl-l-phenyl-2-propane 95.0


Thus the yield of compounds of Formula IVA, was 99 % at a conversion level of 95% (ii) Acylation of compounds of Formula IVA with sodium acetate :
In the second step, the mixture of 95 % 2-chloro-2-methyl-l-phenyl-2-propane and 5 % mixture of 2-methyl-l-phenyl-1-propene and 2-methyl-3-phenyl-2-propene was then taken in a mechanically agitated glass reactor of 15 cm dia and 15 cm height. A mixture of anhydrous sodium acetate in glacial acetic acid, with the molar ratio of 2-chloro-2-methyl-1 -phenyl propane to anhydrous sodium acetate as 1 : 2, and 2-chloro-2-methyl-l-phenyl-2-propane was heated upto 60 °C with continuous stirring at the speed of 1000 rpm The catalyst, tetra butyl ammonium bromide, of 10 weight% of 2-chloro-2-methyl-l-phenyl-2-propane with 12 - 15 ml of water is added to this mixture maintaining the temperature at about 58-60 °C for 10- 12 h.
The reaction mixture is then filtered using vacuum for the recovery of sodium acetate and sodium chloride. The filtrate is then flashed to remove acetic acid under vacuum keeping the base temperature about 25 - 30 ° C. The remaining mixture is then washed with water until the pH of the mixture approaches near neutral condition.
The reaction mixture is then analysed on gas chromatography. The results are given in Table No. 4.
TABLE NO. 4
COMPONENT Weight % by GLC
2-methyl-l-phenyl-1-propene and
2-methyl-3-phenyl-2-propene 77.4
2-methyl-l -phenyl-2-propanol 3.0
2-methyl-1 -phenyl-2-propanol acetate 19.2
This mixture is then taken for the distillation in a distillation unit with the height of packing
2.8 m and column diameter of about 5 cm. The distillation was carried out under constant
vacuum of about 0.01 mm Hg. The first cut was collected at 10 -25 °C which mainly
comprises of compounds of Formula III A. In the second cut compounds of Formula IIA was
collected at 45 - 50 °C. After that mids cut was collected at 52 - 58 °C which comprises of
compounds of Formulae IA, IIA, and III A. And finally compounds of Formula 1A was
collected at about 60 - 80 °C and 0.01 mm Hg. The overall recovery of compounds of


Formula 1A in this step is 98 %.
The overall yield of 2-methyl-l-phenyl-2-propanol acetate based on mixture of 2-methyl-1 -phenyl- 1-propene and 2-methyI-3-phenyl-2-propene obtained is 83.3 % at a overall conversion level of 22.6 % of mixture of 2-methyl-1-phenyl-1-propene and 2-methyl--i-phenyl-2-propene. The yield of 2-methyl-1 -phenyl-2-propanol based on 2-chloro-2-methyl- !-phenyl-2-propane is 13.3 %. Thus the combined overall yield of 2-methyl- l-phenyl-2-propanol acetate and 2-methyl-l-phenyl-2-propanol based on mixture of 2-methyl-1 -phenyl 1-1-propene and 2-methyl-3-phenyl-2-propene is about 96.6 %.
EXAMPLE - III (i) Hydrochlorination of compounds of Formula III with dry hydrogen chloride gas :
300 g of compounds of Formula III was reacted with dry hydrogen chloride gas in
the molar ratio of 1:1 in a mechanically agitated glass reactor, with a dia of 8 cm and a height
of 12 cm having a gas bubbler dip tube. Hydrochlorination of compounds of Formula 111 by
dry hydrogen chloride gas obtained from 35 % hydrochloric acid dehydration with 98 %
sulphuric acid at a temperature in the range of 10 - 15 °C, maintaining the anhydrous
condition, at atmospheric or slightly above the atmospheric pressure, maintaining the
controlled flow of dry hydrogen chloride with constant speed of stirring of 800 rpm, to yield
a mixture containing about 90 - 98 % compounds of Formula IV and 2 - 10 % compounds of
Formula III in the reaction mixture in 5 - 6 h. This mixture is then stored at about 20 - 25 (C
for 24 h. The mixture was then neutralised with anhydrous potassium carbonate. The solids
were then separated with the vacuum filtration. The reaction mixture is then analysed on gas
chromatography and the results are given in Table No. 5.
TABLE NO. 5
COMPONENT Weight % by GLC
2-phenyl-2-propene 8.9
2-chloro-2-phenyl-2-propane 91.0


Thus the yield of compounds of Formula IV based on compounds of Formula III was 99 % at
a conversion level of 91 %.
(ii) Acylation of compounds of Formula IV with sodium acetate :
For the second step, the mixture of 91% 2-chloro-2-phenyl propane and 9% 2-phenyl-2-propene was then taken in a mechanically agitated glass reactor of 15 cm dia and 15 cm height. First, anhydrous sodium acetate is suspended in glacial acetic acid, with the molar ratio of 2-chloro-2-phenyl-2-propane to anhydrous sodium acetate as 1 . 1.5, with continuous stirring at the speed of 800 rpm. The heat of dissolution is removed with the help of cooling water at 20 °C. This mixture is allowed to cool upto 20 °C. Then stoichiometric amount of 2-chloro-2-phenyl propane is added dropwise to this mixture maintaining the temperature at about 23 - 27 °C and stirring continuously for about 2 - 3 h.
The reaction mixture is then filtered using vacuum for the recovery of sodium acetate and sodium chloride. The filtrate is then flashed to remove acetic acid under vacuum keeping the base temperature about 25 - 30 ° C. The remaining mixture is then washed with water until the pH of the mixture approaches near neutral condition.
The reaction mixture is then analysed on gas chromatography. The results are given in Table No. 6.
TABLE NO. 6
COMPONENT Weight % by GLC
2-phenyl-2-propene 28.89
2-phenyl-2-propanol 15.70
2-phenyl-2-propanol acetate 55.30
This mixture is then taken for the distillation in a distillation unit with the height of packing
2.8 m and column diameter of about 5 cm. The distillation was carried out under constant
vacuum of about 0.01 mm Hg, The first cut was collected at 10 -25 °C which mainly
comprises of compounds of Formula III. In the second cut compounds of Formula II was
collected at 45 - 50 °C. After that mids cut was collected at 52 - 58 °C which comprises of
compounds of Formulae I, II, and III. And finally compounds of Formula I was collected at
about 60 - 80 °C and 0.01 mm Hg. The overall recovery of compounds of Formula I in this
step is 98 %.
17

Thus the overall yield of 2-phenyl-2-propanol acetate based on 2-phenyl-2-propene obtained
is about 76.2 % at a overall conversion level of 71.11 % of 2-phenyl propene. The yield of 1-
phenyl-2-propanol based on 2-phenyl-2-propene is about 22.1 %. Thus the combined overall
yield of 2-phenyl-2-propanol acetate and 2-phenyl-2-propanol is about 98.3 %.
EXAMPLE - IV
(T) Hydrochlorination of compounds of Formula HI Awith dry hydrogen chloride gas :
300 g of compounds of Formula IIIA was reacted with dry hydrogen chloride gas n
the molar ratio of 1:1 in a mechanically agitated glass reactor, with a dia of 8 cm and a height
of 12 cm having a gas bubbler dip tube. Hydrochlorination of compounds of Formula IIIA by
dry hydrogen chloride gas obtained from 35 % hydrochloric acid dehydration with 98 %
sulphuric acid at a temperature in the range of 10 - 15 C, maintaining the anhydrous
condition, at atmospheric or slightly above the atmospheric pressure, maintaining the
controlled flow of dry hydrogen chloride with constant speed of stirring of 800 rpm, to yield
a mixture containing about 90 - 98 % compounds of Formula IVA and 2 - 10 % compounds
of Formula IIIA in the reaction mixture in 5 - 6 h. This mixture is then stored at about 20 - 25
°C for 24 h. The mixture was then neutralised with anhydrous potassium carbonate The
solids were then separated with the vacuum filtration. The reaction mixture is then analysed
on gas chromatography and the results are given in Table No. 7.
TABLE NO. 7
COMPONENT Weight % by GLC
2-methyl-1 -phenyl-2-propene 0.5
2-methyl-3-phenyl-2-propene 1.5
2-chloro-2-methyl-1 -phenyl-2-propane 98.0
Thus the yield of compounds of Formula IVA based on compounds of Formula IIIA was 99 % at a conversion level of 98%.


(ii) Acylation of compounds of Formula IVA with sodium acetate .
In second step, the mixture of 98 % 2-chloro-2-methyl-l-phenyl-2-propane and 2 % ~ mixture of 2-methyl-l-phenyl-1-propene and 2-methyl-3-phenyl-2-propene was then taken in a mechanically agitated glass reactor of 15 cm dia and 15 cm height. A mixture of anhydrous sodium acetate in glacial acetic acid, with the molar ratio of 2-chloro-2-methyl- -phenyl-2-propane to anhydrous sodium acetate as 1 : 1.2, and 2-chloro-2-methyl-l-phenyl-2-propane was heated upto 75 °C with continuous stirring at the speed of 800 rpm. The catalyst, tetra butyl ammonium bromide, of 5 weight% of 2-chloro-2-methyl-l-phenyl-2-propane with 12 - 15 ml of water is added to this mixture maintaining the temperature at about 58-60 °C for 10-12 h.
The reaction mixture is then filtered using vacuum for the recovery of sodium acetate and sodium chloride. The filtrate is then flashed to remove acetic acid under vacuum keeping the base temperature about 25 - 30 ° C. The remaining mixture is then washed with water until the pH of the mixture approaches near neutral condition.
The reaction mixture is then analysed on gas chromatography. The results are given in Table No. 8.
TABLE NO. 8
COMPONENT Weight % by GLC
2-methyl-l-phenyl-1-propene and
2-methyl-3-phenyl-2-propene 83.8
2-methyl-l -phenyl-2-propanol 2.7
2-methyl-1 -phenyl-2-propanol acetate 13.0
This mixture is then taken for the distillation in a distillation unit with the height of packing
2.8 m and column diameter of about 5 cm. The distillation was carried out under constant
vacuum of about 0.01 mm Hg. The first cut was collected at 10 -25 °C which mainly
comprises of compounds of Formula IIIA. In the second cut compounds of Formula IIA was
collected at 45 - 50 °C. After that mids cut was collected at 52 - 58 °C which comprises of
compounds of Formulae IA, IIA, and IIIA. And finally compounds of Formula 1A was
collected at about 60 - 80 °C and 0.01 mm Hg. The overall recovery of compounds of
Formula IA in this step is 98 %.
19

The overall yield of 2-methyl-1 -phenyl-2-propanol acetate based on mixture of 2-methyl-1 -
phenyl-1-propene and 2-methyl-3-phenyl-2-propene obtained is 78.64 % at a overall
conversion level of 16.2 % of mixture of 2-methyl-1-phenyl-1-propene and 2-methyl-.^-
phenyl-2-propene. The yield of 2-methyl-1-phenyl-2-propanol based on mixture of 2-methyl -
1-phenyl-1-propene and 2-methyl-3-phenyl-2-propene is 16.67 %. Thus the combined overall
yield of 2-methyl-l-phenyl-2-propanol acetate and 2-methyl-l-phenyl-2-propanol based on
mixture of 2-methyl-1-phenyl-1-propene and 2-methyl-3-phenyl-2-propene is about 95 3 %
EXAMPLE -V
(0 Hydrochlorination of compounds of Formula HI with dry hydrogen chloride gas :
2 kg of compounds of Formula III was reacted with dry hydrogen chloride gas in the molar
ratio of 1:1 in a mechanically agitated glass reactor, with a dia of 15 cm and a height of 20
cm having a gas bubbler dip tube. Hydrochlorination of compounds of Formula 111 by dry
hydrogen chloride gas obtained from 35 % hydrochloric acid dehydration with 98 %
sulphuric acid at a temperature in the range of 10 - 15 °C, maintaining the anhydrous
condition, at atmospheric or slightly above the atmospheric pressure, maintaining the
controlled flow of dry hydrogen chloride with constant speed of stirring of 1000 rpm, TO
yield a mixture containing about 90 - 98 % compounds of Formula IV and 2-10 %
compounds of Formula III in the reaction mixture in 5 - 6 h. This mixture is then stored at
about 20 - 25 °C for 24 h. The mixture was then neutralised with anhydrous potassium
carbonate. The solids were then separated with the vacuum filtration. The reaction mixture is
then analysed on gas chromatography and the results are given in Table No.9.
TABLE NO. 9
COMPONENT Weight % by GLC
2-phenyl-2-propene 13.8
2-chloro-2-phenyl-2-propane 86.2
Thus the yield of compounds of Formula IV based on compounds of Formula III was 99 % at
20

a conversion level of 86 %.
(ii) Acylation of compounds of Formula IV with sodium acetate :
For the second step, the mixture of 86 % 2-chloro-2-phenyl propane and 14 % 7-phenyl-2-propene was then taken in a mechanically agitated glass reactor of 15 cm dia and 15 cm height. First, fused sodium acetate is suspended in 86 % 2-chloro-2-phenyl-2-propane and 14 % 2-phenyl propene, with the molar ratio of 2-chloro-2-phenyl propane to fused sodium acetate as 1 : 3, with continuous stirring at the speed of 1000 rpm. This mixture is heated upto 60 °C. The catalyst, tetra butyl ammonium bromide, of 5 weight% of 2-chloro-2-phenvl propane with 12 - 15 ml of water is added to this mixture maintaining the temperature at about 58 - 60 °C and stirring continuously for about 5 - 6 h.
The reaction mixture is then filtered using vacuum for the recovery of sodium acetate and sodium chloride. The filtrate is then flashed to remove acetic acid under vacuum keeping the base temperature about 25 - 30 ° C. The remaining mixture is then washed with water until the pH of the mixture approaches near neutral condition. The reaction mixture is then analysed on gas chromatography. The results are given in Table
No. 10.
TABLE NO. 10

COMPONENT Weight % by GLC
2-phenyl-2-propene 33.2
2-phenyl-2-propanol 26.4
2-phenyl-2-propanol acetate 39.5
This mixture is then taken for the distillation in a distillation unit with the height of packing 2.8 m and column diameter of about 5 cm. The distillation was carried out under constant vacuum of about 0.01 mm Hg. The first cut was collected at 10 -25 °C which mainly comprises of compounds of Formula III. In the second cut compounds of Formula II was collected at 45 - 50 °C. After that mids cut was collected at 52 - 58 °C which comprises of compounds of Formulae I, II, and III. And finally compounds of Formula I was collected at about 60 - 80 °C and 0,01 mm Hg. The overall recovery of compounds of Formula I in this step is 98%. Thus the overall yield of 2-phenyl-2-propanol acetate based on 2-phenyl-2-propene obtained
21

is about 57.95 % at a overall conversion level of 66.8 % of 2-phenyl propene. The yield of 2-
phenyl-2-propanol based on 2-phenyl-2-propene is about 38.73 %. Thus the combined overall
yield of 2-phenyl-2-propanol acetate and 2-phenyl-2-propanol is about 96.7 %.
EXAMPLE -VI
(i) Hydrochlorination of compounds of Formula IIIA with dry hydrogen chloride gas :
2 kg of compounds of Formula IIIA was reacted with dry hydrogen chloride gas in the molar
ratio of 1.1 in a mechanically agitated glass reactor, with a dia of 15 cm and a height of 20
cm having a gas bubbler dip tube. Hydrochlorination of compounds of Formula IIIA by dry
hydrogen chloride gas obtained from 35 % hydrochloric acid dehydration with 98 %
sulphuric acid at a temperature in the range of 10 - 15 °C, maintaining the anhydrous
condition, at atmospheric or slightly above the atmospheric pressure, maintaining the
controlled flow of dry hydrogen chloride with constant speed of stirring of 1000 rpm. ro
yield a mixture containing about 90 - 98 % compounds of Formula IVA and 2-10 %
compounds of Formula IIIA in the reaction mixture in 5 - 6 h, This mixture is then stored at
about 20 - 25 °C for 24 h. The mixture was then neutralised with anhydrous potassium
carbonate. The solids were then separated with the vacuum filtration. The reaction mixture is
then analysed on gas chromatography and the results are given in Table No. 11.
TABLE NO. 11
COMPONENT Weight % by GLC
2-methyl-1 -phenyl-1 -propene and 0.2
2-methyl-3-phenyl-2-propene 0.8
2-chloro-2-methyl-1 -phenyl-2-propane 99
Thus the yield of compounds of Formula IVA based on compounds of Formula IIIA was 99
% at a conversion level of 99%.
22

(ii) Acylation of compounds of Formula IVA with sodium acetate :
In the second step, the mixture of 99 % 2-chloro-2-methyl-l-phenyl-2-propane and 1 % mixture of 2-methyl-l -phenyl- 1-propene and 2-methyl-3-phenyl-2-propene was then taken in a mechanically agitated glass reactor of 15 cm dia and 15 cm height. A mixture of anhydrous sodium acetate in glacial acetic acid, with the molar ratio of 2-chloro-2-phenyl propane to anhydrous sodium acetate as 1 : 2.5, and 2-chloro-2-methyl-l-phenyl-2-propane was heated upto 60 °C with continuous stirring at the speed of 1000 rpm. The catalyst, tetra butyl ammonium bromide, of 5 weight% of 2-chloro-2-methyl-1 -phenyl-2-propane with 20 -25 ml of water is added to this mixture maintaining temperature at about 58-60 °C for 10 -12h.
The reaction mixture is then filtered using vacuum for the recovery of sodium acetate and sodium chloride. The filtrate is then flashed to remove acetic acid under vacuum keeping the base temperature about 25 - 30 ° C. The remaining mixture is then washed with water until the pH of the mixture approaches near neutral condition. The reaction mixture is then analysed on gas chromatography. The results are given in Table
No. 12.
TABLE NO. 12
COMPONENT Weight % by GLC
2-methyl-1 -phenyl-1 -propene and
2-methyl-3 -phenyl-2-propene 73.80
2-methyl-1 -phenyl-2-propanol 10.82
2-methyl-1 -phenyl-2-propanol acetate 15.18
This mixture is then taken for the distillation in a distillation unit with the height of packing
2.8 m and column diameter of about 5 cm. The distillation was carried out under constant
vacuum of about 0.01 mm Hg. The first cut was collected at 10 -25 °C which mainly
comprises of compounds of Formula III A. In the second cut compounds of Formula IIA was
collected at 45 - 50 °C. After that mids cut was collected at 52 - 58 °C which comprises of
compounds of Formulae I A, IIA, and III A. And finally compounds of Formula 1A was
collected at about 60 - 80 °C and 0.01 mm Hg. The overall recovery of compounds of
Formula IA in this step is 98 %.
23

The overall yield of 2-methyl-1-phenyl-2-propanol acetate based on mixture of 2-methyl-1-phenyl-1-propene and 2-methyl-3-phenyl-2-propene obtained is 56.8 % at a overall conversion level of 26.2 % of mixture of 2-methyl-1-phenyl-1-propene and 2-methyl-3-phenyl-2-propene. The yield of 2-methyl-1-phenyl-2-propanol based on 2-chloro-2-methyl-l-phenyl-2-propane is 40.5 %. Thus the combined overall yield of 2-methyl-l-phenyl-2-propanol acetate and 2-methyl-1-phenyl-2-propanol based on mixture of 2-methyl-1-pheny:-1-propene and 2-methyl-3-phenyl-2-propene is about 97.3 %.
24

We claim :
1. A novel process for the preparation of compounds of Formula I along with small amounts
of compounds of Formula II from compounds of Formula III and a process for the preparation of compounds of Formula IA along with small amounts of compounds of Formula IIA from compounds of Formula IIIA .
(i) Hydrochlorination of the double bond in the Formula III ( or IIIA) under anhydrous condition with dry hydrogen Chloride gas (1:1 molar ratio ) at 0 - 40 °C to form 2-chloro compounds of Formula IV( or IVA), which is then stored at 20 - 25 "C for 24 hours and then neutralised with anhydrous alkali carbonate, separating the excessive solid carbonates;
(ii) Acylating the 2-chloro compounds obtained at the end of step (i) with anhydrous sodium acetate ( 1:1 to 1:4 by wt), suspended in glacial acetic acid, with or without catalyst at 20 - 60 °C for 2- -12 hours to form the compounds of Formula I ( or IA).
(iii) Separating the solids, sodium acetate and sodium chloride, from the acylation reaction mass; removing acetic acid by vacuum distillation at 25 - 30 °C; and washing the organic phase with water till neutral to give the product acetate.
(iv) Separating the compounds of Formula III ( or IIIA), starting materials, from those of Formulae I ( or IA)and II ( or IIA) by distillation [ under vacuum ] at 0.1 to 2 mm Hg.
2. A novel process for manufacture of compounds of Formula I ( or IA)along with small
amounts of compounds of Formula II ( or IIA) from the compounds of Formula III ( or IIIA) as claimed in claim 1.
3. A novel process for manufacture of compounds of Formula I ( or IA) along with small
amounts of compounds of Formula II ( or IIA) from the compounds of Formula III ( or IIIA) as claimed in claim 1.
25

4. A novel process for manufacture of compounds of Formula I ( or IA) along with small
amounts of compounds of Formula II ( or IIA) from the compounds of Formula III ( or IIIA) as claimed in claim 1 wherein in the catalyst employed in step (ii) is a phase transfer catalyst viz. tetra butyl ammonium bromide.
5. A novel process for manufacture of compounds of Formula I ( or IA)along with small
amounts of compounds of Formula II ( or IIA)from the compounds of Formula III ( or IIIA) as claimed in claim 4 wherein, the tetra butyl ammonium bromide catalyst employed in step (ii) is 1 - 5 % by weight of corresponding 2-chloro compounds of Formula IV obtained at the end of step (i).
6. A novel process for manufacture of compounds of Formula I ( or IA)along with small
amounts of compounds of Formula II ( or IIA) from the compounds of Formula III ( or IIIA) as claimed in claim 1 - 5 wherein, the anhydrous sodium acetate used for acylation in step (ii), is 4 - 10 % by weight of the corresponding 2-chloro compounds of Formula IV ( or IVA) obtained at the end of step (i).
7. A novel process for manufacture of compounds of Formula I ( or I A) along with small
amounts of compounds of Formula II ( or IIA) from the compounds of Formula III (or IIIA) as claimed in claim 6 wherein, the sodium used for the acylation in step (ii), is fused sodium acetate, 1:1 to 1:4 by weight of the corresponding 2-chloro compounds of Formula IV ( or IVA) obtained at the end of step (i).
8. A novel process for manufacture of compounds of Formula I (or IA)along with small
amounts of compounds of Formula II ( or IIA) from the compounds of Formula 111 ( or IIIA) as claimed in claim 2 wherein, compounds of Formula I ( or IA) is about 99. s -99.8 % w/w with traces of compound of Formula II ( or IIA) of about 0.1 - 0.5 % w/w and the by-product compound of Formula II ( or IIA) is about 99.5 - 99.9 % w/w at the
26

end of step (iv).
9. A novel process for the preparation of compounds of Formula I along with small amounts of compounds of Formula II from compounds of Formula III and for the preparation of compounds of Formula IA along with small amounts of compounds of Formula IIA from compounds of Formula IIIA, substantially as herein described in the text and in the Examples.
Dated this IT day of June. 2001.
-^
R. M. Pandia, Managing director,
27
Herdillia Chemicals Limited