K. Pilgram
Nov 1, 1980
Citations
0
Influential Citations
6
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
Two novel 2,3-dihydro-1H-imidazo[1,2-b]pyrazole derivatives 7 and 8 have been prepared by hydrazinolysis with 2,4-dinitrophenylhydrazine of 1-(benzylideneamino)-2-(2-ethoxycarbonyl-2-nitromethylidene)-imidazolidine 4. The precursor 4 was conveniently prepared from ethyl nitroacetate and 1-(benzylidene-amino)-2-(methylthio)imidazoline 3. Two examples are presented in which ethyl aceto(and trifluoroaceto)acetate 2-nitrophenyl-hyrazone, 9 and 10, both of which also feature the β-hydrazinoacrylate arrangement, are refluxed in ethanol containing hydrochloric acid and thereby converted into pyrazolones 11 and 12, pyrazoles 13 and 14, and ketone 2-nitrophenylhydrazones 15 and 16, respectively.