Sonogashira-type reactions with 5-chloro-1-phenyl-1H-pyrazole-4- carbaldehydes: A straightforward approach to pyrazolo[4,3-c]pyridines

Article abstract of DOI:10.1002/ejoc.201100626

The easily obtainable 5-chloro-1-phenyl-1H-pyrazole-4-carbaldehydes 2 were used as precursors in Sonogashira-type cross-coupling reactions with various alkynes to provide the corresponding 5-alkynyl-1H-pyrazole-4-carbaldehydes 3. Treatment of these with t