Some New Heterocycles from the Reaction of 4-Carboxaldehyde-2-Phenyl-2H-1,2,3-Triazole Malononitrile

Abstract

Reaction of 4-carboxaldehyde-2-phenyl-2H-1,2,3-triazole 1 with malononitrile in presence of piperidine afforded the triazolomalonitrile 2 which on treatment with hydrazine hydrate, gave 3-amino-5-(2-phenyl-2H-1,2,3-triazol-4-yl)-4,5-dihydro-1-H-pyrazole-4-carbonitrile 3 and with hydroxylamine, gave 5-amino-3-(2-phenyl-2H-1,2,3-triazol-4-yl)-2,3-dihydroisoxazole-4-carbonitrile 4, and with thiourea, gave 2,4-diamino-6-(2-phenyl-2H-1,2,3-triazol-4-yl)-6H-1,3-thiazine-5-carbonitrile 5. Similarly, reaction of 2 with ethanol amine, gave 2-amino-4-(2-phenyl-2H-1,2,3-triazol-4-yl)nicotinonitrile 6, and with thiosemicarbazide, gave 4-amino-2-hydrazinyl-6-(2-phnyl-2H-1,2,3-triazol-4-yl)-6H-1,3-thiazine-carbonitrile 7. Similary reaction of 2 with cyclopentanone gave, 2-amino-4-(2-phenyl-2H-1,2,3-triazol-4-yl)-4,5,6,7-tetrahydrocyclopenta [6] pyran-3-carbonitrile 8. In addition, reaction of 1 with hydrazine hydrate, gave the 4 hydrazone which on treatment with another mole of 1 gave 10 and with 3-carboxaldehyde-1-phenyl-4,5-pyrazolinedione 4 phenylhydrazone gave compound 11.