PRODUCTION OF M-SUBSTITUTED-ALPHA-HYDROXYMETHYLSTYRENE DERIVATIVE AND 3-CHLORO-ALPHA-BROMOSTYRENE

摘要

PROBLEM TO BE SOLVED: To obtain a new compound capable of easily giving a m-substituted-α- hydroxymethylstyrene useful as an intermediate for herbicide, etc., in high yield. SOLUTION: 3-Chloro-α-bromostyrene of formula I. The compound can be produced by reacting 3-chloro-α,β-dibromoethylbenzene of formula II or 3- chloro-α-dibromoethylbenzene of formula III with a base such as potassium hydroxide usually at 0-120 deg.C for 5min to 2hr or by reacting 3-chloroacetophenone of formula IV with phosphorus tribromide preferably at 20-150 deg.C for 30min to 5hr. The m-substituted-α-hydroxymethylstyrene is produced preferably by reacting 3-chloro-α-bromostyrene of formula I with metallic magnesium and reacting the resultant Grignard reagent with formaldehyde or paraformaldehyde.