Abstract We report a new and efficient methodology to prepare N-amino pyrazolo [4, 3-c] pyridin-4-ones 4 and N-amino pyrazolo [3, 4-c] pyridin-4-ones 8 from vic- acetylenyl/hydrazido pyrazoles. The procedure involves the intermediate synthesis of methyl esters of acetylenyl-pyrazole carboxylic acids and the subsequent cyclization under a variety of conditions.
