反应详情

51 μl of thioacetic acid were added to a suspension of 26 mg of sodium hydride (as a 55% w/w dispersion in mineral oil) in 1.4 ml of anhydrous dimethylformamide, whilst ice-cooling, and the resulting mixture was stirred at room temperature for 30 minutes. At the end of this time, a solution of 340 mg of (2S,4R)-4-methanesulfonyloxy-2-{4-[2-(4-nitrobenzyloxycarbonyl)oxyethyl]-1-piperazinylcarbonyl}-1-(4-nitrobenzyloxycarbonyl)pyrrolidine [prepared as described in step (b1) above] in 2 ml of anhydrous dimethylformamide was added to the mixture, and the resulting mixture was stirred at 80°-90° C. for 4 hours, after which the reaction mixture was allowed to cool to room temperature. The reaction mixture was then poured into an aqueous solution of sodium chloride and extracted with ethyl acetate. The extract was washed with water, dried over anhydrous magnesium sulfate and freed from the solvent by distillation under reduced pressure. The residue was purified in a similar manner to that described in step (a), above, to afford the title compound (166 mg). The infra-red absorption spectrum and nuclear magnetic resonance spectrum of the product thus obtained were identical with those of the compound obtained as described in step (a), above.

1. temperaturewhilst ice-cooling
2. stirringthe resulting mixture was stirred at 80°-90° C. for 4 hours
3. temperatureto cool to room temperature
4. extractionextracted with ethyl acetate
5. washThe extract was washed with water
6. dry with materialdried over anhydrous magnesium sulfate
7. distillationfreed from the solvent by distillation under reduced pressure
8. customThe residue was purified in a similar manner to that