反应详情

Triethylamine 33 μl and trichloroacetyl chloride 13 μl were added to a solution of compound (47) 28.9 mg in dichloromethane 2 ml with cooling ice and the mixture was stirred with cooling in ice and at room temperature for 18 h. A saturated sodium hydrogencarbonate solution was added thereto for alkalinization. The mixture was extracted with chloroform. The extracts were washed with brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue obtained was chromatographed on aluminum oxide in chloroform:methanol (97:3) to give the titled compound 26.3 mg as colorless crystals. Yield 98%. Furthermore, the titled compound was recrystallized from methanol-isopropyl ether to give colorless crystals, m.p. 205-207° C.

1. extractionThe mixture was extracted with chloroform
2. washThe extracts were washed with brine
3. dry with materialdried over anhydrous magnesium sulfate
4. concentrationconcentrated under reduced pressure
5. customThe residue obtained
6. customwas chromatographed on aluminum oxide in chloroform:methanol (97:3)