反应详情

In an atmosphere of nitrogen and at −78° C., n-butyl lithium (20.4 ml, 30.0=mol, 1.47 M hexane solution) was added dropwise to a tetrahydrofuran solution (200 ml) of 2-bromothiazole (4.92 g, 30.0 mmol) spending 10 minutes, and the mixture was stirred at the same temperature for 1 hour. To this was added dropwise a tetrahydrofuran solution (50 ml) of N-methyl-N-methoxy-1-[1-(R)-phenylethyl]-5-oxopyrrolidine-3-carboxamide (6.91 g, 25.0 mmol) spending 10 minutes, and the mixture was stirred at −78° C. for 30 minutes and then under ice-cooling for 1 hour. The reaction solution was mixed with 1 mol/l hydrochloric acid (150 ml) under ice-cooling and extracted with ethyl acetate (100 ml×2), and the resulting organic layer was washed with saturated brine (300 ml) and dried over anhydrous sodium sulfate. The solvent was evaporated under a reduced pressure and the residue was applied to a silica gel column chromatography. By eluting with n-hexane:ethyl acetate (1:1), 2.70 g (36%) of the title compound was obtained as a light yellow oil.

1. waitspending 10 minutes
2. stirringthe mixture was stirred at −78° C. for 30 minutes
3. temperatureunder ice-cooling for 1 hour
4. temperaturecooling
5. extractionextracted with ethyl acetate (100 ml×2)
6. washthe resulting organic layer was washed with saturated brine (300 ml)
7. dry with materialdried over anhydrous sodium sulfate
8. customThe solvent was evaporated under a reduced pressure
9. washBy eluting with n-hexane:ethyl acetate (1:1)