HCID 13784978, compound → HCID 14126642, compound

Participants

Reaction Steps

A mixture of 0.5 g of methyl 5-(1-methoxycarbonylethyl)-2-phenylthiophenylacetate [dicarboxylic acid ester] obtained in Example 1-(3) and 5.3 g of polyphosphoric acid (116%) was stirred at a temperature of 60°-80° C. for 6 hours. The mixture was cooled, and to this was added a mixture of ice and water to decompose excessive polyphosphoric acid. The resulting mixture was extracted with ethyl acetate. The organic layer was separated and washed successively with saturated brine solution, aqueous saturated sodium hydrogen carbonate solution and saturated brine solution. The washed extract was dried over anhydrous sodium sulfate. The solvent was distilled off from the dried extract under reduced pressure, and then the residue was recrystallized from a mixture of benzene and hexane to obtain 0.4 g of methyl 2-(10,11-dihydro-10-oxodibenzo[b,f]thiepin-2-yl)propionate (yield 89%), m.p. 81.0°-82.0° C.

Provenance & Evidence