ChemInform Abstract: Efficient One‐Step Synthesis of Substituted‐pyrazolo[3,4‐b]pyridine from Substituted‐3‐cyano‐2(1H)‐pyridone.

Abstract

Fused pyridine derivatives R 0450 Efficient One-Step Synthesis of Substituted-pyrazolo[3,4-b]pyridine from Substituted-3-cyano-2(1H)-pyridone. -Reaction of 5-ethoxycarbonyl-3-cyanopyridone (I) with 80% hydrazine hydrate under reflux affords (II) as the sole product. The formation of the pyrazolopyridine ring is accompanied by an unusual hydrazine-mediated decarboxylation [→ (III)] under more severe conditions. -(ABDEL-GHANY*, Y. S.; HAZZAA, A. A.; GHANI, M. M. A.; KASSEM, Z. A.; Lett. Org. Chem. 5 (2008) 4, 316-318; Dep. Pharm. Chem., Alexandria Univ., Alexandria 21521, Egypt; Eng.) -C. Cyrus 40-150