反应详情

温度

20 °C

The reactor was charged with (4S)-1-(tert-butoxycarbonyl)-4-fluoro-L-prolinamide (116 g, 1 wt, 1 eq.), isopropyl acetate (578 mL, 5 vol), and pyridine (88 mL, 0.8 vol, 2.2 eq). The resulting slurry was stirred at approx. 20° C. Trifluoroacetic anhydride (77 mL, 1.0 wt, 1.1 eq.) was added over at least 30 minutes, maintaining the temperature at approx. 20° C. The reaction solution was stirred an additonal 1 hour at approx. 20° C. Water (578 mL, 5 vol) was added slowly, and the reaction mixture was stirred for 15 minutes. The stirring was stopped, the layers were allowed to separate, and the aqueous (lower) layer was discarded. The organic layer was concentrated under vacuum at a jacket temperature of approximately 50° C. to half volume. The reaction was diluted back up to 5 volumes with isopropyl acetate. The reactor contents were cooled to 20° C., and the reactor was charged with p-toluenesulfonic acid (94 g, 0.8 wt, 1 eq). The reaction was stirred for 2 hours, and GC analysis at this point should show complete consumption of (4S)-1-(tert-butoxycarbonyl)-4-fluoro-L-prolinamide. The reaction was concentrated to 3 volumes under full vacuum at a jacket temperature of approximately 50° C. and 2 volumes of isopropyl alcohol were added. The reaction was concentrated to a final volume of 4 volumes. The reaction was cooled to 0° C. and held for 30 minutes. The solids were collected by filtration, washed with isopropyl alcohol (1 vol), and then dried under vacuum at approx. 50° C. to constant weight. Yield: 68-71%.

1. temperaturemaintaining the temperature at approx. 20° C
2. stirringThe reaction solution was stirred an additonal 1 hour at approx. 20° C
3. stirringthe reaction mixture was stirred for 15 minutes
4. customto separate
5. concentrationThe organic layer was concentrated under vacuum at a jacket temperature of approximately 50° C. to half volume
6. additionThe reaction was diluted back up to 5 volumes with isopropyl acetate
7. temperatureThe reactor contents were cooled to 20° C.
8. stirringThe reaction was stirred for 2 hours
9. customconsumption of (4S)-1-(tert-butoxycarbonyl)-4-fluoro-L-prolinamide
10. concentrationThe reaction was concentrated to 3 volumes under full vacuum at a jacket temperature of approximately 50° C. and 2 volumes of isopropyl alcohol
11. additionwere added
12. concentrationThe reaction was concentrated to a final volume of 4 volumes
13. temperatureThe reaction was cooled to 0° C.
14. filtrationThe solids were collected by filtration
15. washwashed with isopropyl alcohol (1 vol)
16. customdried under vacuum at approx. 50° C. to constant weight