HCID 20211033, compound → HCID 20211026, compound

Participants

Reaction Steps

A mixture of 126 parts of ethyl 3,4-dihydro-2-methyl-4-oxo-2H-1-benzopyran-2-carboxylate and 560 parts of ethanol was hydrogenated at normal pressure and at room temperature with 5 parts of palladium-on-charcoal catalyst 10%. After the calculated amount of hydrogen was taken up, the catalyst was filtered off and the filtrate was evaporated. The residue was distilled, yielding 95.5 parts (80.3%) of ethyl 3,4-dihydro-2-methyl-2H-1-benzopyran-2-carboxylate; bp. 71°-73° C. at 0.5 mm. pressure (intermediate 27).

Provenance & Evidence