Phosphorus oxychloride → Ethyl 4-chloro-1-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylate

Participants

Reaction Steps

A mixture of 5.76 g (20.33 mmol) of ethyl 4-hydroxy-1-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylate and 15.58 g of phosphorus oxychloride was refluxed 1.5 hr, chilled and poured slowly onto crushed ice. The mixture was filtered and the solid washed with ice-water and dried to give 6.0 g of solid, m.p. 89-91° C.

Provenance & Evidence