SU895281A3 - Method of preparing substituted benzhydroles - Google Patents

Abstract

Prepn. of benzhydrol cpds. (I): (in which one or both rings are substd.; X1 and X2 are H, lower alkyl, lower alkoxy or lower alkylthio; A is F, lower alkyl, lower alkoxy, CF3 or OCF3 and n = 0-3), comprises (a) reacting a halobenzene cpd. (II) (in which Hal = Cl, Br or I), with magnesium to form (III): and (b) condensing (III) with a lower alkyl formate HCOOR, (in which R is opt. branched 1-6C alkyl). Process is relatively simple and gives high yields of (I), which are useful intermediates in the prepn. of diarylacetonitriles, diarylhalomethanes and diarylacetic acids.

Description

one

This invention relates to a process for the preparation of tilted benzhydrols of the general formula

hell

(A) n +: if | 1 .ajn

X where X.

same or raztgach-jq

nyv, mean methyl, met-

hydroxy;

L is methyl, methoxy; o or 1.

These benehydrols are widely used as intermediates in the primary synthesis industry.

A known method for producing benzhydroses of the formula, consisting in that 2,4-xylipmagnesium bromide is subjected to interaction with ethyl formate C. The reaction is carried out in sulfuric ether at a temperature of about 0 ° C. In this way, in a known method, with a 7O% yield, only phenol-di- methyl ester (2,4-2

xylyl). In the form of drops, the product di- (2,4-xylip) carbinol is obtained, namely benehydrol of the formula II where X and A are methyl.

The disadvantage of this method is the low yield of the target product.

The purpose of the invention is to improve the yield of the target product.

The goal has been achieved by a method for producing benzhydrols of the general formula 11 consisting in that magnesium is condensed with aryl halide of the general formula

and

Hal

C., X and A have the above

where is the value;

Nab - chlorine or bromine,

in a light-boiled aliphatic or cyclic ether environment, their mixtures at the boiling point of the reaction mass are reacted

Claims (1)

Formula invented 1. The method of teaching substituted hydrons of the general formula I where and Xg are the same or different, are methyl, methoxy; A is methyl, methoxy; And - O or 1, based on the reaction of the interaction of aryl magnesium hapogenide and apkipformate in a medium of a boiling organic solvent, characterized in that, with a chain for increasing the yield of the target product, magnesium is condensed with an aripgapogenide of the general formula ϋ Xl! HBX where X Ί Hag in the environment or their <mass, where A, '^ 2' ^{have the} above meanings; - chlorine or bromine; Г * 2 x ^, HaC the above values are shown, in the medium boiling with ethyl formate of simple aliphatic or simple cyclic ether, at boiling for 1-6 hours, followed by keeping the reaction mixture obtained at this temperature at –5 - О ° С in * sipnate environment.