反应详情

Three hundred milligrams of the compound (VII) obtained in the above procedure (1) were dissolved in 80% trifluoroacetic acid solution and the resulting mixture was stirred at room temperature for 2 hours under a nitrogen gas stream. The reaction mixture was concentrated to dryness and the residue was purified by column chromatography on silica gel (10 g). A colorless oily substance was obtained from a 98:2 eluate of chloroform and methanol. The oily substance was crystallized from a mixed solvent of ethanol and petroleum ether to obtain 170 mg of the title compound as colorless needle-like crystals.

1. concentrationThe reaction mixture was concentrated to dryness
2. customthe residue was purified by column chromatography on silica gel (10 g)
3. customA colorless oily substance was obtained from a 98:2 eluate of chloroform and methanol
4. customThe oily substance was crystallized from a mixed solvent of ethanol and petroleum ether