Reactions of 3-alkylsulfanyl-2-arylazo-3-(1-azacycloalk-1-yl)acrylonitriles with maleimide

Reactions of 2-arylazo-3-(1-azacycloalk-1-yl)-3-methylsulfanylacrylonitriles with male-imide in benzene gave octahydropyrrolo[3,4-a]pyrrolizines 2a–c, decahydro-2,7a-diaza-cyclopenta[a]indene 2e, and decahydro-5-oxa-2,7a-diazacyclopenta[a]indene 2f as a result of 1,3-dipolar cycloaddition. In a similar reaction with 3-allylsulfanyl-2-arylazo-3-(1-azacycloalk-1-yl)acrylonitriles 3, dipolar cycloaddition and intramolecular cyclization competed to give a mixture of compounds 2 (major products) and 1,4,6,7,8,8a-hexahydropyrrolo[2,1-c]-1,2,4-triazines 4b–d, 1,6,7,8,9,9a-hexahydro-4H-pyrido[2,1-c]-1,2,4-triazine 4e, and 1,4,6,7,9,9a-hexahydro-1,4-oxazino[3,4-c]-1,2,4-triazine 4f (minor products).