Thiophene → HCID 57053197, compound

Participants

Reaction Steps

A solution of ethyl 6-oxo-2,3-dimethyl-6H-furo[3,2-h][1]benzopyran-8-carboxylate (0.1 mol) in methanol (250 ml) was hydrogenated for 10 hours at 170° C. (pressurized) with palladium on activated carbon, palladium content 5% (2 g) as a catalyst in the presence of a 4% thiophene solution (10 ml). After uptake of hydrogen (3 equiv), the catalyst was filtered off and the filtrate was evaporated. The residue was purified by flash column chromatography over silica gel (eluent: CH2Cl2). The desired fractions were collected and the solvent was evaporated, yielding 20 g (72.9%) of (±)-ethyl 7,8-dihydro-2,3-dimethyl-6H-furo[3,2-h][1]benzopyran-8-carboxylate (interm. 16-a).

Provenance & Evidence