反应详情

To a mixed solution of trifluoroacetic acid (5 ml), chloroform (1.5 ml) and water (2.5 ml) was added a solution of the compound obtained in Step 2 (560 mg) in chloroform (1 ml) under cooling with ice water. After stirring for 1.5 hours under cooling with ice water, the reaction mixture was adjusted to pH 8 with saturated aqueous solution of sodium hydrogencarbonate and extracted with diethyl ether. The organic layer was dried over anhydrous sodium sulfate and thereafter the solvent was distilled off under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluent; n-hexane:ethyl acetate=5:1–2:1) to obtain the title compound (240 mg).

1. extractionextracted with diethyl ether
2. dry with materialThe organic layer was dried over anhydrous sodium sulfate
3. distillationthe solvent was distilled off under reduced pressure
4. customThe resulting residue was purified by silica gel column chromatography (eluent; n-hexane:ethyl acetate=5:1–2:1)