Synthesis of New 2-[(Substituted-pyrazol-1-yl)carbonyl]-thieno[2,3b]pyridine Derivatives Using 1,3-Diketones,Alkylethoxymethylenes and Ketene Dithioacetals

The reaction of 3-amino-4,6-dimethyl-2-thieno2,3-b]pyridine carbohydrazide ( 1 ) with appropriate 1,3-diketones 2a-2d in glacial acetic acid afforded 3-amino-2-(3,5-disubstituted-pyrazo)-1-yl)carbonyl]-4,6-dimethylthieno2,3-b]pyridines 3a-3d. 3-Amino-2-(5-amino-3,4-disubstituted-pyrazol-1-yl)carbonyl]-4,6-dimethylthieno2,3-b]pyridines 5a-5h were also prepared by treatment of carbohydrazide 1 with appropriate alkylethoxymethylenes and ketene dithioacetals 4a-4h , respectively.