Reaction of ethyl 3‐ethoxymethylene‐2,4‐dioxovalerate with monosubstituted hydrazines

Abstract

Reactions of ethyl 3‐ethoxymethylene‐2,4‐dioxovalerate (1) with phenyl‐ and methylhydrazines are described. While the reaction of 1 with phenylhydrazine gave a mixture of ethyl 4‐acetyl‐1‐phenylpyrazole‐5‐carboxylate (4) and ethyl 5‐methyl‐1‐phenylpyrazole‐4‐glyoxylate (5), 1 reacted with methylhydrazine to give ethyl 4‐acetyl‐1‐methylpyrazole‐3‐carboxylate (14) as the sole product.

2-Substituted-8-methyl-3,6-dihydroimidazo[4,5-c]pyrazolo[3,4-e]pyridazine as an anti-inflammatory agent

“…Various synthetic routes have been followed for synthesizing the fused ring pyrazolo-pyridazine system and their derivatives (Druey, 1958;Caronna et al, 1986;Kobayashi et al, 1971;Kasuga et al, 1974;Shawali, 1977;Kurihara et al, 1980). The synthesis of pyridazines from 1,4-diketones and hydrazine hydrate is one of the best known procedures (Hendrickson et al, 1964).…”