反应详情

Vilsmeier reagent was prepared by treatment of DMF (0.56 ml, 7.2 mM) in dichloromethane (35 ml) under argon with oxalyl chloride (0.58 ml, 6.6 mM) at -10° for 30 minutes. The (2S,4S)-4-acetylthio-1-allyloxycarbonyl-2-carboxypyrrolidine was added to this in one portion, followed by N-methylmorpholine (0.87 ml, 7.9 mM) and stirring continued for 30 minutes at -10°. After cooling to -20°, allyl 3-allyloxy-4-aminobenzoate (1.54 g, 6.6 mM) plus N-methyl morpholine (0.87 ml, 7.9 mM) dissolved in dichloromethane (20 ml) were added dropwise. The temperature was allowed to rise to 5° and stirring continued for 2 hours. After dilution with dichloromethane, the mixture was washed with a 2M aqueous solution of hydrochloric acid, water and a saturated aqueous solution of sodium bicarbonate. It was dried over MgSO4 and the solvent evaporated. Crude material was purified by medium pressure chromatography using a gradient of diethyl ether (0 to 10%) in dichloromethane to give (2S,4S)-4-acetylthio-1-allyloxycarbonyl-2-(4-allyloxycarbonyl-2-allyloxyphenylcarbamoyl)pyrrolidine (2.7 g).

1. temperatureAfter cooling to -20°
2. additionwere added dropwise
3. customto rise to 5°
4. stirringstirring
5. waitcontinued for 2 hours
6. washAfter dilution with dichloromethane, the mixture was washed with a 2M aqueous solution of hydrochloric acid, water
7. dry with materialIt was dried over MgSO4
8. customthe solvent evaporated
9. customCrude material was purified by medium pressure chromatography