Chlorohydrin prodn. from olefin(s) - by reaction with N-chloro-sulphonamidate in aq. medium

摘要

Prepn. of chlorohydrins is carried out by reacting olefinic cpds. of formula R1CH=CHR2 (I) with metal N-chlorosulphonamidates of formula R-Ar-SO2-N(Cl)M (II) in an aq. medium contg. an acid whose conjugate base is non-nucleophilic (where R is H, 1-10C alkyl or halogen; Ar is a divalent aromatic gp. having 1 or more rings; M is an alkali metal; R1 and R2 are H or 1-30C alkyl opt. substd. by one or more halogen atoms or carboxylic acid, ester or nitrile gps., or R1+R2 can form a ring). The reaction is pref. effected at 40-60 deg.C in the liq. phase, opt. in the presence of a non-nucleophilic solvent (e.g. acetone). The (II):(I) molar ratio is pref. 1:1. (II) is suitably "Chloramine T". The acid is pref. H2SO4, H3PO4 or a sulphonic acid and is used in an amt. of 1 mole per mole of (II). The process is highly selective, giving high chlorohydrin yields (e.g. 66-77%).