Methyl chloroformate → 2-Amino-3-(2-methyl-6-methoxycarbonylaminobenzylideneamino)pyridine

Participants

Reaction Steps

To a solution of 2,3-diaminopyridine (546 mg) and 2-methyl-6-methoxycarbonylaminobenzaldehyde (966 mg)*, which was prepared by reacting 2-methyl-6-aminobenzaldehyde with methyl chloroformate according to a similar manner to that of Preparation 2, and triethylamine (2.5 g) in methylene chloride (26 ml) was added a 0.5M solution of titanium tetrachloride in methylene chloride (6 ml) at 0° C. and the mixture was stirred for 2 hours at the same temperature. To the mixture, water was added and the insoluble materials were removed by filtration, and the organic layer was separated. The solvent was evaporated under reduced pressure. The residue was subjected to column chromatography on silica gel (27 g), eluting with a mixture of chloroform and methanol (50:1). The fractions containing the desired product were combined and the solvent was removed under reduced pressure. The residue was triturated with diethyl ether to give 2-amino-3-(2-methyl-6-methoxycarbonylaminobenzylideneamino)pyridine (279 mg).

Provenance & Evidence