Chemistry Letters

Synthesis and Unambiguous Assignment of Structure to Pyrano [4, 3-c] pyrazol-4 (1H)-ones and-4 (2H)-ones

…, A Pla, F Sanchez-Ferrando, A Virgili

Index: Cantos, Albert; March, Pere De; Moreno-Manas, Marcial; Pla, Anna; Sanchez-Ferrando, Francisco; Virgili, Albert Chemistry Letters, 1986 , p. 295 - 298

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Citation Number: 2

Abstract

A clean synthesis of pyranopyrazolones is described. The reactions of 4-chloro-3-(1- chlorovinyl)-6-methyl-2-pyrone with arylhydrazines give pyrano [4, 3-c] pyrazol-4 (2H)-ones as the only identified products. However, the isomeric pyrano [4, 3-c] pyrazol-4 (1H)-ones have been isolated when alkylhydrazines were used. Unambiguous assignment of structure could be achieved by homonuclear 1 H {1 H} NOE determinations.