Hydrochloric Acid → (3R,4R)-1-Benzylpyrrolidine-3,4-diol

Temperature

70 °C

Boron trifluoride ethyl etherate (36 ml, 0.29 mol) in diglyme (150 ml) was cooled to 0+ C. (3S,4S)-1-Benzyl-3,4-dihydroxy-2,5-dioxopyrrolidine (16 g, 72 mmol) and sodium borohydride were added slowly. The mixture was stirred at 70° C. for 2 hours. 6 N hydrochloric acid (100 ml) was added slowly and the mixture was heated at 70° C. for 15 minutes. Sodium fluoride (44.5 g, 1 mol) was added and the mixture was heated at reflux temperature for 1/2 hour. The mixture was cooled to room temperature. 20% Aqueous sodium hydroxide (85 ml) was added and the resulting mixture was filtered. The organic phase was isolated and evaporated to dryness. The residue was partitioned between water and diethyl ether. The water phase was extracted with ether (4×500 ml). The collected organic phases were dried over magnesium sulphate and evaporated to dryness. Recrystallization from ethyl acetate (25 ml) gave (3R,4R)-1-benzyl-3,4-pyrrolidinediol (12.3 g, yield: 88%) as white crystals.

1. temperaturethe mixture was heated at 70° C. for 15 minutes
2. temperaturethe mixture was heated
3. temperatureat reflux temperature for 1/2 hour
4. temperatureThe mixture was cooled to room temperature
5. filtrationthe resulting mixture was filtered
6. customThe organic phase was isolated
7. customevaporated to dryness
8. customThe residue was partitioned between water and diethyl ether
9. extractionThe water phase was extracted with ether (4×500 ml)
10. dry with materialThe collected organic phases were dried over magnesium sulphate
11. customevaporated to dryness
12. customRecrystallization from ethyl acetate (25 ml)

ORD record

ord-56c361664c61468a881f2136098271aa

Source dataset

uspto-grants-1999_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05952363