PREPARATION OF 2: 4-DICHLOROPHENOXYACETIC ACID (2: 4-D)

Two different methods of preparation of 2:4-D are reported. The first method consists in the nuclear chlorination of the phenoxyacetic acid by the action of dichlorocarbamide. prepared in a modified way. The other method consists in the conversion of phenol into 2 : 4-dichlorophenol through the different stages of nitration, reduction, diazotisation and then coupling with cuprou. chloride. The 2 : 4-dichlorophenoI. thus obtained, is then converted into 2 : 4-D with chlaroacetic acid in presence of alkali. Both the reactions give good yields of the dichloro derivative.