A Simple Synthesis of 6-Phenylpyrano[2,3-c]pyrazol-4(1H)-ones

Wilfried Becker; Gernot A. Eller; Wolfgang Holzer

doi:10.1055/s-2005-872078

PAPER

A Simple Synthesis of 6-Phenylpyrano[2,3-c]pyrazol-4(1H)-ones

Wilfried Becker, Gernot A. Eller, Wolfgang Holzer*
Department of Drug Synthesis, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
Fax: +43(1)42779556; e-Mail: wolfgang.holzer@univie.ac.at;

Abstract

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Abstract

A novel synthesis of substituted 6-phenylpyrano[2,3-c]pyrazol-4(1H)-ones via reaction of various 2-substituted or 2,5-disubstituted 2,4-dihydro-3H-pyrazol-3-ones with phenylpropynoyl chloride using calcium hydroxide in refluxing 1,4-dioxane is described. N-Unsubstituted representatives were obtained by treatment of 4-methoxybenzyl-protected congeners with trifluoroacetic acid.

Key words

pyrazolones - acylations - cyclizations - fused-ring systems - PMB protecting group

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Referenzen

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