4-Chlorobenzenesulfonyl chloride → 2-{[(4-Chlorophenyl)sulfonyl]amino}-4,5-dimethoxybenzoic acid

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Reaction Conditions

Reaction Steps

33.71 g (0.32 mol) of sodium carbonate were dissolved in 250 ml of water and warmed to 60° C. 25.00 g (0.13 mol) of 2-amino-4,5-dimethoxy-benzoic acid were introduced into the solution, and to this solution 29.55 g (0.14 mol) of 4-chloro-benzenesulfonyl chloride were added portionwise over 15 min. After cooling the mixture was filtered with suction, the residue was taken up in 1% sodium hydrogencarbonate solution, the solution filtered, and the product precipitated by addition of 1 N hydrochloric acid. 25.90 g (55%) of 2-(4-chloro-phenylsulfonylamino)-4,5-dimethoxy-benzoic acid of melting point (m.p.) 212-214° C. were obtained.

Provenance & Evidence