反应详情

To a solution of a mixture of (cis)-1-(2,4-dimethoxybenzyl)-4-methyl-5-oxopyrrolidine-3-carboxylic acid methyl ester and (trans)-1-(2,4-dimethoxybenzyl)-4-methyl-5-oxopyrrolidine-3-carboxylic acid methyl ester (14.2 g) in methanol (150 ml) was added sodium methoxide (about 5M solution in methanol, 28 ml), and the mixture was stirred at room temperature for 16 hours, and then heated to 55° C. and stirred for 3 hours. To this reaction solution was added sodium methoxide (about 5M solution in methanol, 10 ml), and the mixture was stirred at 55° C. for additional 2 hours. This reaction solution was cooled to room temperature, and then water (50 ml) was added thereto, and the mixture was stirred overnight. The reaction solution was concentrated under reduced pressure to remove methanol. To the resulting residue was added a 2M aqueous solution of hydrochloric acid (105 ml), and the mixture was extracted with ethyl acetate (300 ml). The resulting organic layer was washed with a saturated aqueous solution of sodium chloride, and then dried over anhydrous sodium sulfate, and concentrated under reduced pressure to give a crude product of the titled compound (14.0 g).

1. temperatureheated to 55° C.
2. stirringstirred for 3 hours
3. stirringthe mixture was stirred at 55° C. for additional 2 hours
4. temperatureThis reaction solution was cooled to room temperature
5. stirringthe mixture was stirred overnight
6. concentrationThe reaction solution was concentrated under reduced pressure
7. customto remove methanol
8. additionTo the resulting residue was added a 2M aqueous solution of hydrochloric acid (105 ml)
9. extractionthe mixture was extracted with ethyl acetate (300 ml)
10. washThe resulting organic layer was washed with a saturated aqueous solution of sodium chloride
11. dry with materialdried over anhydrous sodium sulfate
12. concentrationconcentrated under reduced pressure