One-step synthesis of diarylpyrazolo[3,4-b]pyridines from isoflavones.

A new concise, facile, and efficient method for the synthesis of 3-hydroxy-5,6-diphenylpyrazolo[3,4-b]pyridine derivatives has been described. The cyclocondensation of isoflavones with 3-amino-5-hydroxypyrazole in the presence of sodium methoxide gave fused heteroaromatic 3-hydroxy-5,6-diphenylpyrazolo[3,4-b]pyridines in moderate to good yields.