HCID 10245979, compound → HCID 54397933, compound

Reaction equation

[CH2:1]([O:3][C:4]([C:6]1[C:7](=[O:23])[O:8][C:9]2[CH:21]=[CH:20][C:19]([Cl:22])=[CH:18][C:10]=2[C:11]=1[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:5])[CH3:2].[H][H]>C(O)C.[Pt]=O>[CH2:1]([O:3][C:4]([CH:6]1[CH:11]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[C:10]2[CH:18]=[C:19]([Cl:22])[CH:20]=[CH:21][C:9]=2[O:8][C:7]1=[O:23])=[O:5])[CH3:2]

Participants

Procedure

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).