| abstract |
2,4-Dichloro-3-alkyl-6-nitrophenols which are useful as intermediate of cyan couplers in color photography are prepared by sulfonating 4-chloro-3-alkyl-phenols to obtain 5-chloro-4-alkylhydroxybenzenesulfonic acids, chlorinating the acids in an aqueous phase to obtain 3,5-dichloro-4-alkyl-2-hydroxybenzenesulfonic acids and nitrating the sulfonic acids. |