Heterocyclization of Vis-Substituted Hydroxamic Acid Salts of Acetylenyl-Pyrazoles: A New Procedure for the Preparation of Pyrazolo[3,4-c]Pyridin-7-Ones

摘要

Procedures for the preparation of 5-substituted pyrazolo[3,4-c]pyridin-7-ones and 5-substituted 6-hydroxypyrazolo[3,4-c]pyridin-7-ones have been developed based on heterocyclization of vic-acetylenylpyrazolylhydroxamic acids under the influence of copper(I) salts in dimethylformamide or with organic bases in butanol or methanol.