Synthesis of new 2-[(Substituted-pyrazolin-1-yl)carbonyl]-thieno[2,3-o]pyridine derivatives

Article abstract of DOI:10.1002/jccs.199900012

The reaction of 3-amino-4,6-dimethyl-2-thieno[2,3-b]pyridine carbohydrazide (1) with appropriate chalcones 2a-2d in the presence of acid catalyst produced the corresponding 3-amino-2-[(3,5-disubstituted-pyrazolin-1-yl)carbonyl]-4,6-dimethylthieno[2,3-b] pyridines 3a-3d. 3-Amino-2-[(3-substituted-pyrazolin-l-yl)carbonyl]-4,6-dimethylthieno[2,3-b] pyridines 7a, 7b were also obtained by the cyclization reaction of carbohydrazide 1 with Mannich base derivatives 6a, 6b under basic condition.