Borane;tetrahydrofuran → HCID 18427823, compound

Participants

Reaction Steps

Under an atmosphere of nitrogen, 825 mg (2.17 mmol) of 1-benzyl-4-[3-(tert-butoxycarbonylamino)-1,1-difluorocyclobutan-3-yl]-2-pyrrolidone (Isomer F2) was dissolved in 20 ml of tetrahydrofuran to which, while cooling in an ice bath with stirring, was subsequently added 6.51 ml of 1 N borane-tetrahydrofuran complex tetrahydrofuran solution. Ten minutes thereafter, the ice bath was detached and the reaction mixture was stirred at room temperature for 18 hours. After evaporation of the solvent under a reduced pressure, the thus obtained residue was mixed with 30 ml of 80% ethanol and 3 ml of triethylamine and heated under reflux for 2 hours. After evaporation of the solvent under a reduced pressure, the thus obtained residue was mixed with ethyl acetate and saturated sodium bicarbonate aqueous solution to effect separation of layers. The organic layer was washed with saturated brine, the aqueous layer was extracted with ethyl acetate and then the organic layers were combined and dried over anhydrous sodium sulfate. After filtration, the solvent was evaporated under a reduced pressure and the resulting residue was purified by a silica gel column chromatography to give 494 mg (62.2%) of the title compound. 1H-NMR data of the thus obtained compound coincided with the aforementioned data of its enantiomer Isomer F1.

Provenance & Evidence