反应详情

To a suspension of sodium hydride (62.8% dispersion in mineral oil, 285 mg) in N,N-dimethylformamide (30 ml) was added thioacetic S-acid (0.54 ml) at 0°-5° C. under an atmosphere of nitrogen. After evolution of hydrogen ceased, the mixture was stirred at room temperature, and (2S,4R)-2-(2-aminothiazol-4-yl)-4-methanesulfonyloxy1-(4-nitrobenzyloxycarbonyl)pyrrolidine (1.6 g) in N,N-dimethylformamide (20 ml) was added thereto. The mixture was stirred at 90° C. for 5 hours and poured into a mixture of ethyl acetate (100 ml) and water (100 ml). The aqueous layer was separated and extracted twice with ethyl acetate (50 ml). The organic layers were combined, washed with brine, dried over magnesium sulfate and concentrated under reduced pressure to give a syrup. The syrup was subjected to a column chromatography on silica gel (60 g) eluting with a mixture of acetone and dichloromethane (1:5 V/V) to give (2S,4S)-4-acetylthio-2-(2-aminothiazol-4-yl)-1 -(4-nitrobenzyloxycarbonyl)pyrrolidine (1.26 g).

1. stirringThe mixture was stirred at 90° C. for 5 hours
2. customThe aqueous layer was separated
3. extractionextracted twice with ethyl acetate (50 ml)
4. washwashed with brine
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. customto give a syrup
8. washeluting with a mixture of acetone and dichloromethane (1:5 V/V)