Sodium Hydroxide → HCID 57758718, compound

Temperature

60 °C

To a solution of the methyl 4-ethyl-3-methyl-5-oxo-1-[(R)-1-phenylethyl]pyrrolidin-3-yl-carboxylate (stereoisomer A) produced in Reference Example 32 (10.63 g, 36.7 mmol) in tetrahydrofuran (330 mL) and methanol (110 mL), 2N aqueous solution of sodium hydroxide (110 mL, 220 mmol) was added at room temperature, and the mixture was stirred in an oil bath at 60° C. for 5.5 hours. The reaction mixture was concentrated under reduced pressure, and after adding concentrated hydrochloric acid to the concentrate in an ice bath for acidification, the mixture was extracted with chloroform (300 mL+2×100 mL). The organic layers were combined, and dried with anhydrous sodium sulfate. After removing the dessicating agent by filtration, the solvent was removed by distillation under reduced pressure to obtain 11.46 g (quantitative) of the crude title compound as a pale brown solid. The crude product was used in the subsequent reaction with no further purification.

1. additionwas added at room temperature
2. concentrationThe reaction mixture was concentrated under reduced pressure
3. additionafter adding concentrated hydrochloric acid to the
4. concentrationconcentrate in an ice bath for acidification
5. extractionthe mixture was extracted with chloroform (300 mL+2×100 mL)
6. dry with materialdried with anhydrous sodium sulfate
7. customAfter removing the dessicating agent
8. filtrationby filtration
9. customthe solvent was removed by distillation under reduced pressure

ORD record

ord-eaef9c45d5dc4dab9a053cb1ed05017e

Source dataset

uspto-grants-2012_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08211910B2