Synthesis of Pyrido[2′,3′: 3,4]pyrazolo[1,5-a]pyrimidine, Pyrido[2′,3′:3,4] pyrazolo[5,1-c][1,2,4]triazine, and Pyrazolyl Oxadiazolylthieno[2,3-b] pyridine Derivatives

6-(2-Thienyl)-4-(trifluoromethyl)-1H-pyrazolo[3,4-b]pyridine-3-amine reacted with different active methylene compounds to afford pyridopyrazolopyrimidine derivatives. On the other hand, it reacted with some halo compounds to give the imidazo[1,2:1,5]pyrazolo[3,4-b]pyridine derivatives. Also, it diazotized to give the corresponding diazonium chloride that is coupled with several active methylene compounds to give the corresponding triazine derivatives. Furthermore, compound 3-amino-6-(2(thienyl)-4-(trifluoromethyl)thieno[2,3-b]pyridine-2-carbohydrazide reacted with some -dicarbonyl compounds and some sulfur-containing compounds to afford the corresponding pyrazolyl oxadiazolylthieno[2,3-b]pyridine derivatives.