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.