Potassium Carbonate → (S)-benzyl 1-(2-tert-butoxy-2-oxoethyl)pyrrolidine-2-carboxylate

HRID 70882

Reaction equation

HRID 70882 reaction equation
Cl.[NH:2]1[CH2:6][CH2:5][CH2:4][C@H:3]1[C:7]([O:9][CH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)=[O:8].C([O-])([O-])=O.[K+].[K+].Br[CH2:24][C:25]([O:27][C:28]([CH3:31])([CH3:30])[CH3:29])=[O:26]>CN(C=O)C>[C:28]([O:27][C:25](=[O:26])[CH2:24][N:2]1[CH2:6][CH2:5][CH2:4][C@H:3]1[C:7]([O:9][CH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)=[O:8])([CH3:31])([CH3:30])[CH3:29]

Participants

5

Reactant 3

HCID 11430Potassium Carbonate2×HCID 79177tert-Butyl bromoacetateHCID 2733413Proline benzyl ester hydrochloride

Product 1

HCID 59607548(S)-benzyl 1-(2-tert-butoxy-2-oxoethyl)pyrrolidine-2-carboxylateYield 49.4%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a suspension of (S)-benzyl pyrrolidine-2-carboxylate hydrochloride (700 mg, 2.90 mmol) and K2CO3 (1201 mg, 8.69 mmol) in DMF (7 ml), t-butyl bromoacetate (0.535 ml, 3.62 mmol) is added. After stirring for 71 hours, aqueous K2CO3 (1.5 g of K2CO3/40 ml of H2O) is added to the reaction mixture. The products are extracted with EtOAc. The organic layer is washed twice with water and once with brine, dried over K2CO3, filtered, and concentrated to give (S)-benzyl 1-(2-tert-butoxy-2-oxoethyl)pyrrolidine-2-carboxylate (458 mg); HPLC retention time=1.38 minutes (condition D); MS (m+1)=320.2; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.44 (s, 9 H) 1.81-2.03 (m, 3 H) 2.13-2.14 (m, 1 H) 2.82-2.88 (m, 1 H) 3.13-3.17 (m, 1 H) 3.46 (A of AB, J=17.3 Hz, 1 H) 3.49 (B of AB, J=17.3 Hz, 1 H) 3.73 (dd, J=8.8 and 4.8 Hz, 1 H) 5.15 (A of AB, J=12.4 Hz, 1 H) 5.17 (B of AB, J=12.4 Hz, 1 H) 7.29-7.38 (m, 5 H).

Workup

  1. additionis added
  2. extractionThe products are extracted with EtOAc
  3. washThe organic layer is washed twice with water and once with brine
  4. dry with materialdried over K2CO3
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-e5818882a6164ceba0db737e26bdcea1
Source dataset
uspto-grants-2014_09
Patent number
US08822534B2

Linked notes

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