反应详情

In18 ml of dimethylformamide, was dissolved 8.18 g (22.0 mmol) of (3S,4S)-1-carboxymethyl-4-[(1R)-1-(p-chlorophenylthiocarbonyl)ethyl]-3-[(1R)-1-hydroxyethyl]-2-azetidinone at room temperature. To the resulting solution, were successively added 5.5 ml (40.0 mmol) of pivaloyloxymethyl chloride and 5.75 g (40.3 mmol) of sodium iodide, and was added dropwise 4.2 ml (25.3 mmol) of diisopropylethylamine, followed by stirring the mixture for 20 hours at the same temperature. The reaction mixture was diluted with 120 ml of toluene. The toluene solution was washed with 2.5% aqueous sodium bicarbonate solution and water, each several times. The resulting toluene solution was dried over sodium sulfate, and then the solvent was removed by evaporation. The resulting oily residue was dissolved in 60 ml of toluene at room temperature. To the resulting solution was added 120 ml of hexane, precipitating a crystal, which was filtered and washed to obtain 9.46 g of a white crystal of the title compound (yield: 92.7%).

1. washThe toluene solution was washed with 2.5% aqueous sodium bicarbonate solution and water
2. dry with materialThe resulting toluene solution was dried over sodium sulfate
3. customthe solvent was removed by evaporation
4. dissolutionThe resulting oily residue was dissolved in 60 ml of toluene at room temperature
5. additionTo the resulting solution was added 120 ml of hexane
6. customprecipitating a crystal, which
7. filtrationwas filtered
8. washwashed