Methanol → tert-butyl (2R)-2-ethynylpyrrolidine-1-carboxylate

HRID 846662Notes

Reaction equation

HRID 846662 reaction equation
C([Li])CCC.Br[C:7](Br)=[CH:8][C@H:9]1[CH2:13][CH2:12][CH2:11][N:10]1[C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15].CO.C(OCC)(=O)C>C1COCC1>[C:8]([C@H:9]1[CH2:13][CH2:12][CH2:11][N:10]1[C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])#[CH:7]

Participants

6

Reactant 4

HCID 887MethanolHCID 8857Ethyl AcetateHCID 14730282Tert-butyl (2r)-2-(2,2-dibromovinyl)pyrrolidine-1-carboxylateHCID 178418339Butyllithium

Product 1

HCID 10262067tert-butyl (2R)-2-ethynylpyrrolidine-1-carboxylateYield 88.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Butyl lithium (48 mL, 0.08 mol) was added at -78° C. to a stirred solution of (R)-t-butyl 2-(2,2-dibromoethenyl)-1-pyrrolidinecarboxylate (14.2 g, 0.04 mol) in dry THF (300 mL). The color turned to dark yellow. After 15 min. methanol (10 mL) and ethyl acetate (10 mL) were added and the solution was allowed to warm to room temperature. The solvent was removed and the residue was partitioned between ethyl acetate and water. The ethyl acetate phase was concentrated and applied to a silica gel column. Elution with ethyl acetate:Skellysolve B (1:10) gave 6.9 g (88%) of product as a yellow oil.

Workup

  1. customThe solvent was removed
  2. customthe residue was partitioned between ethyl acetate and water
  3. concentrationThe ethyl acetate phase was concentrated
  4. washElution with ethyl acetate:Skellysolve B (1:10)

Sources & evidence

ORD record
ord-dfaf558adf06464ca9dc531203c44fd4
Source dataset
uspto-grants-1992_08
Patent number
US05137905

Reaction notes

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