A process for the preparation of N-carboxymethylene-4-chloro-anthranilic acid, and dialkyl esters thereof

A process for preparing N-carboxymethylene-4-chloro-anthranilic acid and its dialkyl esters is characterised in that 2,4-dichlorobenzoic acid is reacted with glycin in the presence of a base, a solvent and a catalyst, yielding N-carboxymethylene-4-chloro-anthranilic acid, and this acid is optionally reacted with a dialkyl sulphate, a dialkyl carbonate or an alkyl halide in the presence of a base and a solvent, yielding its dialkyl ester.