R. Aggarwal, R. Kumar, Shiv P. Singh
Oct 1, 2009
Citations
1
Influential Citations
12
Citations
Journal
Journal of Fluorine Chemistry
Abstract
Abstract The reaction of 2-hydrazino-3-methylquinoxaline 1 with trifluoromethyl-β-diketones 2 not only yields the expected 5-trifluoromethyl-5-hydroxy-Δ 2 -pyrazolines 3a – 3f and/or 3-trifluoromethylpyrazoles 4c – 4f but also the unexpected products 1,2,4-triazolo[4,3- a ]quinoxalines 5a – 5f and/or 3(5)-trifluoromethyl-1 H -pyrazoles 6c – 6f . Furthermore, the acid-catalyzed dehydration of 5-hydroxypyrazolines 3a – 3b resulted in the formation of unexpected 5a – 5b along with the expected corresponding pyrazoles 7a – 7b . These unprecedented observations provide evidence for the existence of equilibrium between the hydroxypyrazoline 3 and its open chain tautomer, ketoimine 9 in the mechanistic path leading to the formation of pyrazoles 7 and triazoles 5 .