Reaction of 5-aminopyrazoles with β-dimethylaminopropiophenones. Synthesis of new pyrazolo[3,4-b]pyridines

Article abstract of DOI:10.1002/jhet.5570350213

Several new pyrazolo[3,4-b]pyridines were obtained from the reaction of 5-amino-1-aryl-3-methylpyrazoles 1 with β-dimethylaminopropiophenones 2 in pyridine. The structure elucidation of 4,5-dihydropyrazolo[3,4-b]pyridines 3 is based on nmr measurements and X-ray diffraction. The treatment of compounds 3 with N-bromosuccinimide led to the formation of pyrazolo[3,4- b]pyridines 4.