GB755676A - Improvements in or relating to the halogenation of phenols - Google Patents

Abstract

A process for producing a para-halophenol comprises reacting a phenol with a sulphonyl halide in the liquid phase in the presence of a metal halide at a temperature not in excess of 75 DEG C. The phenol may be one of the general formula <FORM:0755676/IV(a)/1> where Y is a hydrogen atom, a hydroxy group, an ether group such as an alkoxy or an aryloxy group, an alkyl group, an amino group or a mono- or di-substituted amino group, or an organic group containing amino, nitro, halo or hydroxy groups; a list of phenols which may be employed is given. The sulphuryl halide may be sulphuryl chloride, bromide, iodide or fluoride, and the metallic halide may be a chloride, bromide, iodide or fluoride of aluminium, iron, zinc, tin or titanium. Examples describe the preparation of 4-chloro-2-methyl phenol from ortho-cresol; para-chlorocatechol from catechol; 4-chloro-2-methoxy phenol from guaiacol; 4 - chloro - 2 - cyclohexoxy - phenol from ortho - cyclo - hexoxy - phenol; 4 - chloro-2 - cyclohexyl phenol from ortho - cyclohexyl phenol; 4 - chloro - 2 - aminophenol from ortho - amino - phenol; 4 - chloro - 2-(N - methylamino) phenol from ortho (N-methylamino) phenol; 4 - chloro - 2 - (diethylamino) phenol from ortho - (diethylamino) phenol; 4 - chloro - 2 - (dimethylaminoethoxy) phenol from ortho (dimethylaminoethoxy) phenol; ortho, ortho1 - oxy - di - para - chlorophenol from ortho - ortho1 - oxy - diphenol; ortho, ortho1 - ethylene - di - para - chlorophenol from ortho, ortho1 - ethylenediphenol; and 4 - chloro - 2 - (methylmercapto) phenol from ortho-methyl-mercapto-phenol. Metal halides used in the examples are ferric chloride and aluminium chloride. The preparation of 4-chloro-2-methyl-phenoxyacetic acid from 4-chloro-methyl phenol and monochloroacetic acid is also described.