HCID 10245979, compound → HCID 54397933, compound

Participants

Reaction Steps

To a solution of 6-chloro-2-oxo-4-phenyl-2H-1-benzopyran-3-carboxylic acid ethyl ester (4.4 g) in ethanol (300 ml) was added platinum oxide (0.30 g), followed by stirring at room temperature in a hydrogen atmosphere (3 to 4 atm) for 3 hours. After the catalyst was filtered off, the filtrate was distilled to remove the solvent, followed by treatment of the residue with isopropyl ether, to yield 6-chloro-3,4-dihydro-2-oxo-4-phenyl-2H-1-benzopyran-3-carboxylic acid ethyl ester as colorless crystals (2.24 g).

Provenance & Evidence