Ethanol → HCID 20211033, compound

Participants

Reaction Steps

A mixture of 152 parts of 3,4-dihydro-2-methyl-4-oxo-2H-1-benzopyran-2-carboxylic acid, 18.4 parts of concentrate sulfuric acid and 2720 parts of ethanol was stirred overnight at reflux temperature. The reaction mixture was evaporated and the residue was taken up in a mixture of 1,1'-oxybisethane and a sodium hydroxide solution. The organic layer was separated, washed with water, dried, filtered and evaporated. The residue was purified by column chromatography over silica gel using trichloromethane as eluent. The pure fractions were collected and the eluent was evaporated, yielding 126 parts (72.7%) of ethyl 3,4-dihydro-2-methyl-4-oxo-2H-1-benzopyran-2-carboxylate as a residue (intermediate 26).

Provenance & Evidence