反应详情

To a mixture of alcohol of formula (9) (50 g) and triphenyl phosphine (151 g) in THF (2.5 L) diisopropyl azodicarboxylate (116.5 g) in THF (500 mL) was added at 15-20° C. and maintained at that temperature for 1-2 hours. About 5% lithium hydroxide solution (1000 mL) was added into the reaction mass and extracted with MTBE (3×750 mL) to remove the organic impurities. The pH of the aqueous layer was adjusted to 1-4 by dilute hydrochloric acid (250 mL). The reaction mass was maintained at RT for 5-6 hours and the product was filtered off. The crude product was taken with IPA (7.5 vol) and added water (22.5 vol). The reaction mass was then maintained at RT for 12-14 hours. The solid was filtered and dried at 50-55° C. for 10-12 hours to afford the title compound.

1. additionwas added at 15-20° C.
2. temperaturemaintained at that temperature for 1-2 hours
3. extractionextracted with MTBE (3×750 mL)
4. customto remove the organic impurities
5. filtrationthe product was filtered off
6. additionadded water (22.5 vol)
7. temperatureThe reaction mass was then maintained at RT for 12-14 hours
8. filtrationThe solid was filtered
9. customdried at 50-55° C. for 10-12 hours