Chlorination of N-acyl Derivatives of p-Aminophenols (Naphthols) and p-Phenylenediamines

The chlorination of N-acyl derivatives of p-aminophenols can provide either N-acyl-2,3,6-trichloro-4-aminophenols or N-acyl-2,3,5,6-tetrachloro-1,4-benzoquinone imines depending on solvent nature, process temperature, and molar ratio initial compound-chlorine. The chlorination of N-acyl-4-amino-1-naphthols affords only N-acyl-2,3-dichloro-1,4-naphthoquinone imines. N,N'-Diacyl-1,4-phenylenediamines give rise on chlorination to a mixture of 2,5-dichloro-, 2,6-dichloro-, and 2,3-dichloro-N,N'-diacyl-1,4-phenylenediamines.