Citric Acid → N-[[[N-(4-chloro-o-tolyl)-formimidoyl]methylamino]thio]-N-methyl-p-toluenesulfonamide

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Reaction Steps

To a stirred solution cooled to -10° of 18.5 g. (0.1 mole) of N-methyl-p-toluenesulfonamide and 10.1 g. (0.1 mole) of triethylamine in 300 ml. of methylene chloride is added dropwise 10.3 g. (0.1 mole) sulfur dichloride. The reaction mixture is stirred at ambient temperature for 0.5 hour and cooled to 10°. A solution of 18.3 g (0.1 mole) of N-methyl-N'-(4-chloro-o-tolyl)formamidine and 10.1 g. (0.1 mole) triethylamine in 100 ml. of methylene chloride is added rapidly with stirring. The reaction mixture is stirred at ambient temperature for 0.5 hour and extracted successively with 300 ml. of water, 300 ml. aqueous citric acid solution containing 10.5 g. (0.05 mole) of citric acid, and 300 ml. of water. The organic layer is dried and the solvent removed under reduced pressure. The residue is chromatographed over 100 g. silica gel using Hexane:Et2O:Et3N (18:2:3 by volume) to obtain 3.2 g. (8% yield) of N-[[[N-(4-chloro-o-tolyl)-formimidoyl]methylamino]thio]-N-methyl-p-toluenesulfonamide as a viscous oil.

Provenance & Evidence