4-Hydroxy-6-oxo-3-phenyl-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic acid ethyl ester → 4-hydroxy-3-phenyl-7H-thieno[2,3-b]pyridin-6-one

Participants

Reaction Conditions

Reaction Steps

4-Hydroxy-6-oxo-3-phenyl-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic acid ethyl ester (1.5 g, 4.76 mmol) was refluxed in 2M sodium hydroxide (50 ml) for 5 hr, filtered while still hot, then cooled to 0° C. and acidified to pH 1 by addition of conc. HCl. The resultant white precipitate was filtered and dried to give 4-hydroxy-3-phenyl-7H-thieno[2,3-b]pyridin-6-one as a white solid. Yield=1.05 g (90.7%).

Provenance & Evidence