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

HRID 354273

Reaction equation

HRID 354273 reaction equation
[C:1]([N:8]1[CH2:14][CH2:13][CH2:12][C@H:9]1[CH:10]=O)([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.[C:34](Br)(Br)([Br:36])[Br:35].C([O-])(O)=O.[Na+]>C(Cl)Cl>[C:4]([O:3][C:1]([N:8]1[CH2:14][CH2:13][CH2:12][CH:9]1[CH:10]=[C:34]([Br:36])[Br:35])=[O:2])([CH3:7])([CH3:6])[CH3:5]

Participants

6

Reactant 4

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 516892Sodium BicarbonateHCID 2734674tert-butyl (2S)-2-formylpyrrolidine-1-carboxylate

Product 1

HCID 14730280tert-Butyl 2-(2,2-dibromoethenyl)pyrrolidine-1-carboxylateYield 74%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a stirred cold (minus 50° C.) solution of N-boc-prolinal (5.98 g, 30 mmol) and PPh3 (62.95 g, 240 mmol) in CH2Cl2 (200 mL) was slowly added a solution of CBr4 (39.80 g, 120 mmol) in CH2Cl2 (50 mL), and the stirring was continued for 1 hr at 0° C. To this mixture was added sat. NaHCO3 and the mixture was extracted with CHCl3. The extract was washed with H2O, dried over MgSO4, and evaporated. The residue was chromatographed on silica-gel with CHCl3 and n-hexane-AcOEt (4:1, v/v) as eluent to give 7.84 g (74%) 1-(tert-butoxycarbonyl)-2-(2,2-dibromoethenyl)pyrrolidine as colorless plates. mp 61-63; IR (KBr) 1693 cm−1; 1H-NMR (CDCl3) δ1.46 (9 H, s), 1.72-2.19 (4H, m), 3.35-3.45 (2H, m),4.35 (1H, br s), 6.36 (1H, br s); MS (FAB) m/z 352, 354, 356, 358; Anal. Calcd. for C11H17NO2Br2: C, 37.21; H 4.83; N, 3.94. Found: C, 37.14; H, 4.83; N, 4.00.

Workup

  1. extractionthe mixture was extracted with CHCl3
  2. washThe extract was washed with H2O
  3. dry with materialdried over MgSO4
  4. customevaporated
  5. customThe residue was chromatographed on silica-gel with CHCl3 and n-hexane-AcOEt (4:1

Sources & evidence

ORD record
ord-219a0646edd146d4988ad7f4c23f81f1
Source dataset
uspto-grants-2004_06
Patent number
US06756378B2

Linked notes

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