Water → HCID 10778296, compound

Participants

Reaction Steps

In methanol (20 ml) was suspended ethyl 6,7-di-methoxy-3,4-dihydro-1H-2-benzothiopyran-4-one-1-carboxylate (6 g) followed by addition of 2N-KOH (15 ml) and the mixture was stirred at room temperature for one hour. The reaction mixture was then poured into water, acidified and extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried (MgSO4) and the solvent was distilled off to give 6,7-dimethoxy-3,4-dihydro-1H-2-benzothiopyran-4-one-1-carboxylic acid (4.4 g, yield 82%). Recrystallization from methanol gave colorless prisms. m.p. 212°-213° C.

Provenance & Evidence