tert-Butyl 2-(2,2-dibromoethenyl)pyrrolidine-1-carboxylate → tert-Butyl 2-ethynylpyrrolidine-1-carboxylate

HRID 354274

Reaction equation

HRID 354274 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:12][CH2:11][CH2:10][CH:9]1[CH:13]=[C:14](Br)Br)=[O:7])([CH3:4])([CH3:3])[CH3:2].[Li]CCCC>C1COCC1>[C:1]([O:5][C:6]([N:8]1[CH2:12][CH2:11][CH2:10][CH:9]1[C:13]#[CH:14])=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 14730280tert-Butyl 2-(2,2-dibromoethenyl)pyrrolidine-1-carboxylateHCID 178418339Butyllithium

Product 1

HCID 14730283tert-Butyl 2-ethynylpyrrolidine-1-carboxylateYield 97%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a stirred cold (minus 78° C.) solution of 1-(tert-butoxycarbonyl)-2-(2,2-dibromoethenyl)pyrrolidine (7.81 g, 22 mmol) in THF (200 mL) was added n-BuLi (1.59 M in hexane, 28 mL, 44 mmol) over 10 min. and the stirring was continued for 2 hr at the same temp. The reaction was quenched by the addition of sat. NH4Cl and extracted with EtOAc. The extract was washed with brine, dried over MgSO4, and evaporated. The residue was chromatographed on silica-gel with n-hexane-AcOEt (10:1, v/v) as eluent to give 4.15 g (97%) 1-(tert-butoxycarbonyl)-2-ethynyl pyrrolidine as a light yellow oil. 1H-NMR (CDCl3) δ1.48 (9 H, s), 1.82-2.21 (4 H, m), 3.30-3.45 (2 H, m), 4.41-4.52 (1 H, m).

Workup

  1. customThe reaction was quenched by the addition of sat. NH4Cl
  2. extractionextracted with EtOAc
  3. washThe extract was washed with brine
  4. dry with materialdried over MgSO4
  5. customevaporated
  6. customThe residue was chromatographed on silica-gel with n-hexane-AcOEt (10:1

Sources & evidence

ORD record
ord-6076674b8c2e46b9bd8735b53ecc9621
Source dataset
uspto-grants-2004_06
Patent number
US06756378B2

Linked notes

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