Reaction #45909

Reaction equation

borane tetrahydrofuran

tert-Butyl {(3S)-3-methyl-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidin-3-yl}carbamate

Ethanol

triethylamine

→

compound

Yield 85.0%

tert-Butyl {(3S)-3-methyl-1-[(1R)-1-phenylethyl]pyrrolidin-3-yl}carbamate

Yield 85.0%

Solvents

tetrahydrofuran

water

Conditions

Workup

1. 1
   workup.ADDITIONwas added
2. 2
   workup.STIRRINGby stirring in an oil bath at 90° C. for 3 hours
3. 3
   OtherThe reaction liquid
4. 4
   Concentrationwas concentrated under reduced pressure
5. 5
   workup.DISSOLUTIONdissolved in ethyl acetate
6. 6
   Washwashed with an aqueous saturated sodium hydrogencarbonate solution and saturated brine
7. 7
   DryingAfter drying over anhydrous sodium sulfate
8. 8
   Otherthe insoluble matter was separated by filtration
9. 9
   Otherthe residue obtained by concentration
10. 10
    Otherwas purified by silica gel column chromatography (eluent, n-hexane

Procedure

tert-Butyl {(3S)-3-methyl-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidin-3-yl}carbamate (I-343) (500 mg, 1.57 mmol) was dissolved in tetrahydrofuran (15 ml), and with cooling with ice, borane/tetrahydrofuran complex (1.2 mol/l tetrahydrofuran solution) (3.93 ml, 4.71 mmol) was added, followed by stirring at room temperature for 17 hours. Ethanol (12 ml), triethylamine (4 ml) and water (4 ml) were added to the reaction liquid, followed by stirring in an oil bath at 90° C. for 3 hours. The reaction liquid was concentrated under reduced pressure, dissolved in ethyl acetate, and washed with an aqueous saturated sodium hydrogencarbonate solution and saturated brine. After drying over anhydrous sodium sulfate, the insoluble matter was separated by filtration, and the residue obtained by concentration was purified by silica gel column chromatography (eluent, n-hexane:ethyl acetate=2:1→1:2, v/v) to obtain the entitled compound (406 mg, 85%) as a colorless oily substance.

Source