Sodium hydride → 4-Hydroxy-6-oxo-3-phenyl-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic acid ethyl ester

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Reaction Steps

2-(2-Ethoxycarbonyl-acetylamino)-4-phenyl-thiophene-3-carboxylic acid ethyl ester (5.0 g, 13.8 mmol) and sodium hydride (1.1 g, 27.7 mmol) in anhydrous THF (120 ml) were refluxed for 6 hr under nitrogen. On cooling, solvents were removed in vacuo and the residue suspended in water (100 ml). The mixture was acidified by addition of concentrated hydrochloric acid (5 ml) and stirred for 1 hr. The precipitate was filtered and dried, then recrystallised from ethanol to give 4-hydroxy-6-oxo-3-phenyl-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic acid ethyl ester as a pale yellow solid. Yield=2.59 g (63.3%).

Provenance & Evidence