Synthesis of 3-Substituted Pyrazolopyridines by Electrophilic Reactions

Article abstract of DOI:10.3987/COM-94-6757

Reactions of pyrazolo<1,5-a>pyridines with Eschenmoser's salt, activated alkenes and alkynes, and chlorosulfonyl isocyanate provided general routes to 3-substituted pyrazolo<1,5-a>pyridines such as 3-dimethylaminomethyl- and 3-(2-nitroethyl)pyrazolo<1,5-a>pyridines, 1-phenyl-3-(pyrazolo<1,5-a>pyrid-3-yl)-2-propen-1-ones, 4-(pyrazolo<1,5-a>pyrid-3-yl)-3-buten-2-one, pyrazolo<1,5-a>pyridine-3-carboxamide, and pyrazolo<1,5-a>pyridine-3-carbonitrile.