Reactions of 4-chloro-5H-1,2,3-dithiazole-5-thione with alpha,beta-unsaturated beta-amino esters: Formation of 2-[2-(1-alkenylsulfanyl-1-alkoxycarbonyl-2-amino)-1,2-dicyano-vinylsulfa nyl]-3-amino-2-alkenoic alkyl esters

Abstract

Treatment of 4-chloro-5H-1,2,3 -dithiazole-5 -thione with alkyl 3-alkyl (or aryl)-3-amino-2-propenoates in the presence of pyridine (2 equivalents) in dichloromethane at reflux gave 2-[2-(1-alkenylsulfanyl-1-alkoxy-carbonyl-2-amino)-1,2-dicyanovinylsulfanyl]- 4 and -1,2-dicyanovinyldisulfanyl]-3-amino-2-alkenoic alkyl esters 7 in 16 to 60% and 8 to 48% yields, respectively.