Sulfanilic acid catalysed one‐pot three‐component Mannich reaction for synthesis of β‐amino ketones

Abstract We have reported sulfanilic acid as an exceedingly competent catalyst for one‐pot Mannich reaction to give β‐amino carbonyl compounds in good to excellent yield within a short reaction time. The various organic acids have screened; like gallic acid, 4‐hydroxy benzoic acid, 4‐amino benzoic acid, phenylacetic acid, chloroacetic acid, sulfosalicylic acid, sulfanilic acid, chloro benzoic acid, phthalic acid, salicylic acid, cinnamic acid, hippuric acid, 1‐naphthyl acetic acid, o‐amino benzoic acid, p‐TSA, succinic acid, malic acid, and among them sulfanilic acid is a suitable catalyst. The reaction condition was optimized with respect to the solvent, the amount of catalyst as well as the variation of the ketone, aldehyde, and amine substrates. The procedure is mild, effective, ecofriendly, and the use of the minimum amount of catalyst.