We report in this paper the synthesis of 6-substituted pyrazolo [4, 3-c] pyridin-4-ones, 6- substituted 5-hydroxypyrazolo [4, 3-c] pyridin-6-ones, 5-substituted pyrazolo [3, 4-c] pyridin-7- ones and 5-substituted 6-hydroxypyrazolo [3, 4-c] pyridin-7-ones by heterocyclization of vic- acetylenylpyrazol-hydroxamic acids under the influence of copper (I) salt in dimethylformamide or with organic bases in butanol or methanol.