Koji Saito, I. Hori, M. Igarashi
Feb 1, 1974
Citations
0
Influential Citations
8
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
The reaction of ethyl ethoxymethylenecyanoacetate with its hydrazino derivative in the presence of pyridine in ethanol at room temperature gave ethyl (4-ethoxycarbonyl-5-aminopyrazol-1-yl)methylenecyanoacetate(6) and two geometric isomers of ethyl (4-ethoxycarbonylpyrazol-5-ylamino)methylenecyanoacetate(7). Compound 6 itself, under the same conditions, rearranged to compound 7. Both compounds, 6 and 7, upon heating cyclized exclusively to the same product, diethyl 7-aminopyrazolo[1,5-a]pyrimidine-3,6-dicarboxylate(8). From the results of other combination reactions on methylenecyanoacetic ester homologs, a plausible reaction mechanism involving a rearrangement is discussed.