The chlorination of some 2,6-substituted 4-chlorophenols; X-ray crystal structure of (E)-(2RS,5RS)-2,4,5,6,6-Pentachloro-2-methyl-6-nitrohex-3-enoic acid

Abstract

Chlorination of 4-chloro-2-methyl-6-nitrophenol (4) with chlorine in acetic acid containing concentrated hydrochloric acid gives the epimeric acyclic carboxylic acids (6) and (7). The structure of compound (6) was determined by X-ray crystal structure analysis. No such acyclic compounds are formed in similar chlorinations of 2,4-dichloro-6-nitrophenol (13a) or 2,4-dichloro-6-methylphenol (13b). The mode of formation of compounds (6) and (7) is discussed.