DE1275041B - Process for the preparation of ª ‡ -hydroxyisopropylbenzenes - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

German class:

Number:
File number:
Registration date:
Display day:

C07c

12 ο-S / 02
12 ο-2/01

P 12 75 041.3-42 (B 85587)

January 28, 1966

August 14, 1968

It is known that α-Hydroxyisopropylbenzenes can be produced by air oxidation of isopropylbenzenes via hydroperoxide intermediates. Here, however, either the not harmless hydroperoxides have to be isolated, or else the process gives only moderate yields. In addition, the products obtained are impure.

Furthermore, from the "Journal of the General Chemistry of the USSR", English edition, vol. 28 (1958), p. 3228 ff., Known to represent the reaction of benzene carboxylic acid esters with methylmagnesium bromide. However, this method is only of scientific interest.

It has now been found that one can elegantly a-Hydroxyisopropylbenzenes by hydrolysis of α-Chloroisopropylbenzenes are obtained when α-chloroisopropylbenzenes are used with more than 0.5 times the weight of water at temperatures below + 40 ° C implements.

It is surprising that excellent yields are obtained with the new process, since as is known, -chloroisopropylbenzenes readily form isopropenylbenzenes with elimination of hydrogen chloride and decompose their low molecular weight polymers.

Suitable -chloroisopropylbenzenes are, for example, α-chloroisopropylbenzene and -chloroisopropylbenzene, which has one or more alkyl substituents on the benzene nucleus, in particular alkyl groups with 1 to 4 carbon atoms, such as in the compounds p-methyl-α-chloroisopropylbenzene, m-isopropyl-α-chloroisopropylbenzene and 2,4,5-triethyl-α-chloroisopropylbenzene. In particular, di- (<x -chloroisopropyl) benzenes can be used, such as o-, m- and preferably p-di - («- chloroisopropyl) benzene, κ - chloroisopropylbenzenes are obtained by chlorination of isopropylbenzenes, for example according to the German Patent specification 1 022 203 described manner, easily accessible. The production of di - ( «- chloroisopropyl) benzenes is carried out in an analogous manner by chlorination of diisopropylbenzenes at temperatures of -10 to + 4O ⁰ C, preferably -5 to +15 ⁰ C, under exposure to visible or UV light, wherein it is expedient to work in the absence of solvents. The products obtainable in this way are very pure and give particularly high yields when converted by the present process.

Water is used in more than 0.5 times, preferably 1 to 20 times, in particular 1 to 5 times, by weight, based on the starting material. If smaller amounts are used, the reaction is incomplete. Very high amounts of water no longer bring any further advantages. Process for the production of
α-hydroxyisopropylbenzenes

Applicant:

Aniline & Soda Factory in Baden
Aktiengesellschaft, 6700 Ludwigshafen

Named as inventor:

Dr. Franz Reicheneder,

Dr. Hugo Fuchs,

Dr. Georg Krusche, 6700 Ludwigshafen, Germany

in particular then is the processing of the accumulating

ao hydrochloric acid solution no longer worthwhile. Intensive mixing of the important in both phases. It is advisable to use small amounts of commercially available versus diluted ones aqueous acids to stable emulsifiers, or else

»5 one works with the addition of water-soluble organic substances Solvents that reduce the solubility of α-chloroisopropylbenzene increase in the aqueous phase. Suitable water-soluble solvents are, for example lower alcohols, ketones, cyclic ethers, nitriles, acid amides or sulphate oxides. For example methanol, ethanol, isopropanol, acetone, butanone, tetrahydrofuran, dioxane, acetonitrile, form * amide, dimethylformamide, pyrrolidone and dimethyl sulfoxide. The solvent is generally used in 0.5 to 5 times the amount by weight, based on water.

The reaction is carried out at a temperature below + 4O ⁰ C, advantageously at -10 to + 3O ⁰ C, in particular at 0 to 25 ° C. At lower temperatures, the reaction rate is very slow; at higher temperatures, isopropenylbenzenes or their low molecular weight polymers are increasingly isolated in place of the α-hydroxyisopropylbenzenes.

To carry out the method, for example in a stirred vessel, the a-chloroisopropylbenzene, Water and optionally the solvent for some time, for example 10 minutes to 24 hours, mixed at reaction temperature. The organic phase is separated off. Dissolved in the aqueous phase Residues can be isolated, for example, by extraction with a water-insoluble solvent.

809 590/459

Claims (1)

Optionally after the removal of the mitver- at about 5 ⁰ C. The reaction solution is at The product obtained can then be mixed with 100 parts of ice water under vigorous solvent in many cases added without further purification of the intermediate stirring. After filtering off the resulting product can be used for further conversions. a precipitate one receives about 70 parts of α, α'-di- To remove traces of unreacted starting materials 5 hydroxy-1,3-diisopropylbenzene. From the mother liquor if necessary, cleaning can be carried out by extraction with methylene chloride Isolate another 30 parts of the crude product by crystallization or distillation. Overall you get lation under reduced pressure. 100 parts of a, a'-dihydroxy-1,3-diisopropylbenzene vom The parts mentioned in the examples are by weight melting point 128 ⁰ C, that is 85% of theory, parts, ίο based on 100 weight percent α, α'-di- For the preparation described in the examples, chlorine-1,3-diisopropylbenzene. the a-chloroisoanalysis serving as starting compounds propylbenzenes, no protection is claimed. ~,. ', "", ", ■, ■" .. ^ *, - ,, ^{F y} * ^y Found ... C 74.2, H 9.4, O 16.7; B ei sρ ie 1 1 calculated ... C74.3, H 9.3, O 16.5. 200 parts of 1,4-diisopropylbenzene have a molecular weight of 194. Stirring vessel provided with gas inlet tube and example 3 Thermometer, presented. The contents of the flask are indicated by - a UV lamp type »Osram 125 W HQA« irradiated. 70 parts of α-chloroisopropylbenzene are passed into a chlorine gas, diluted with about the 20 mixture of 80 parts of acetone and 80 parts of water, 2 to 5 times the amount of nitrogen, introduced through the 1,4-diiso. After stirring for 4 hours at 0 to 5 ° C propylbenzene. The internal temperature is taken up in methylene chloride and dried at about 0 to + 5 ° C kept. The chlorination is so long sodium sulfate. After removing the solution, continue until a crystal slurry has formed, which is distilled by means of "the residue is just left to mix in the oil pump. Then vacuum. 55 parts of α-hydroxyisopropyl are obtained from the 1,4-di- (" chloro- benzene, bp. _Oil = 63 ⁰ C (melting point = 21 ° C, isopropyl) benzene, and sets the mother liquor to nff = 1.5240). the yield is 89% of theory, further chlorination again. This Process becomes analvse
repeated until the 1,4-diisopropyl- ^{y used} benzene is practically completely chlorinated. 30 rounds are obtained ... C 78, /, H 8, y, υ 11.1; in this way 258 parts 1,4-di - («- chloroisopropyl) - calculated ... C 79.4, H 8.8, O 11.8. Benzene with a temperature of 59 ° C, that is 90% of theory, molecular weight 136. based on 1,4-diisopropylbenzene used. Example 4 Analysis of the crude product: - cat, ·, ^ ₁ - 1.1 - λ λ- iu 1 j fVfntiri ™ ( "?" ■ TT7 9 ri9Q4- ³⁵ 50 Parts, "a ^ l ^ dichloro--dnsopropylbenzol be solved -Gefunden ... C63,2, H7,2 Cl29,4. 100 parts of ethanol and 100 parts of water _: calculated ... C 62.4, H 6.93, Cl 30.7. _{and stirred for 5 hours at 25} o _{C The solution} ^ _an _ 600 parts of the a, a'-dichloro-l, 4-diiso obtained in this way, closing with water to 3 times the volume of verpropylbenzene are thinned in a mixture of 800 parts and shaken out with benzene. One receives after Dissolved water and 1200 parts of acetone, and for 5 hours the solvent distilling off 20 parts of α, οί'-DibeiÖ ° C vigorously stirred. Then you move the. hydroxy-1,4-diisopropylbenzene = 47% of theory. Reaction solution with ice water and still turbines. The melting point of the crude product is 118 bis once vigorously. The precipitating low 122 ° C. The product still contains small quantities blow is sucked off and dried. Diisopropenylbenzene from the filtrate. By recrystallization can be obtained by shaking out with ether or methylene with a mixture of benzene and cyclohexane (1: 3) Chloride still in solution «,« - Dihydroxy-1,4 "this must be separated off, Isolate diisopropylbenzene. Overall you get 445 parts with a melting point of 133 to 135 ° C, that is the claim: 88% of theory. The product is sufficiently pure for further reactions. 50 Process for the production of a-Hydroxyiso-Analvse * propylbenzenes by saponification of a-ChlorisorWnmiPTi Γ738 HQO 017 5 · propylbenzenes, characterized by ... L lifi, Ά y, u, υ l /, 5, _{ne tj that one Ä} _chlorisopropylbenzenes with the calculated ... C / 4, J, H y, j, υ 16.5. _{more a] g 0) 5 times the} amount by weight of water temperatures below 194. 55 + converts 4O ⁰ C with molecular weight. Considered publications: 140 parts of a, a'-dichloro-1,3-diisopropylbenzene, Belgian Patent No. 439,797; by chlorination of 1,3-diisopropylbenzene analogous to French patent specification No. 861 835; the procedure described in Example 1, fresh 60 U.S. Patent No. 2,819,319; are prepared in 140 parts of acetone and Journal of the American Chemical Society, 42 140 parts of water dissolved. Then stir for 24 hours (1920), p. 2064. 809 590/459 8.68 © Bundesdnickerei Berlin