反应详情

温度

100 °C

Lawesson's reagent (90 mg) was added to a toluene (5 ml) solution of Compound 20a (140 mg). The obtained mixture was stirred at 100° C. in a nitrogen atmosphere for 1 hour. After the reaction was over, the reaction mixture was allowed to cool, and concentrated. The obtained residue was purified by column chromatography (5% ethyl acetate/n-hexane). Fractions containing the ester body of Compound 4 were collected, and concentrated to dryness. As a result, 126 mg of yellow solid was obtained. The obtained yellow solid (90 mg) was, without further purification, dissolved in ethanol (1 ml). A 1N sodium hydroxide aqueous solution (1 ml) was added thereto in a nitrogen atmosphere. The obtained mixture was stirred under heating at 45° C. for 1 hour. After the reaction was over, the mixture was allowed to cool, and a 1N hydrochloric acid aqueous solution was added thereto. The mixture was separated with ethyl acetate and water. The organic layer was washed once with water and once with a saturated sodium chloride solution, and then dried over anhydrous sodium sulfate. The solvent was distilled off, and as a result, Compound 20 (54 mg, 64%) was obtained as an opalescent solid.

1. temperatureto cool
2. concentrationconcentrated
3. customThe obtained residue was purified by column chromatography (5% ethyl acetate/n-hexane)
4. additionFractions containing the ester body of Compound 4
5. customwere collected
6. concentrationconcentrated to dryness