Methane → HCID 21270128, compound

Participants

Reaction Steps

7,8-Dihydroxy-3-(3-methylphenyl)-4H-1-benzopyran-4-one (100 mg), dissolved in a mixture of ethanol/dioxan 2:1 (75 ml), is hydrogenated for 24 h at room temperature over palladium 10% on active charcoal (50 mg) in the presence of p-toluenesulphonic acid monohydrate (50 mg). After filtration of the catalyst, the filtrate is evaporated under vacuum to a minimum volume, then diluted with water (75 ml) and neutralized to pH 7 by addition of a saturated solution of NaHCO3. An oil is obtained which is extracted with ethyl acetate. The extract is dried over magnsium sulphate and evaporated under vacuum to yield an amorphous solid which is dissolved in methylene chloride and eluted on a silica gel column. After evaporation of the main fraction, one obtains 3,4-dihydro-7,8-dihydroxy-3-(3-methylphenyl)-2H-1-benzopyran, m.p. 95°-96°.

Provenance & Evidence