Ammonium Chloride → tert-Butyl 3-ethenylpyrrolidine-1-carboxylate

HRID 11749Notes

Reaction equation

HRID 11749 reaction equation
C([Li])CCC.[Br-].C1([C:13]([PH3+])([C:20]2[CH:25]=[CH:24]C=[CH:22][CH:21]=2)C2C=CC=CC=2)C=CC=CC=1.[C:27]([O:31][C:32]([N:34]1CCC(C=O)C1)=[O:33])([CH3:30])([CH3:29])[CH3:28].[Cl-].[NH4+]>CCCCCC.O1CCCC1.C(OCC)(=O)C>[C:27]([O:31][C:32]([N:34]1[CH2:24][CH2:25][CH:20]([CH:21]=[CH2:22])[CH2:13]1)=[O:33])([CH3:30])([CH3:29])[CH3:28]

Participants

8

Reactant 4

HCID 25517Ammonium ChlorideHCID 4692112(+-)-1-(tert-Butoxycarbonyl)pyrrolidine-3-carboxaldehydeHCID 21951224Triphenylmethyl phosphonium bromideHCID 178418339Butyllithium

Product 1

HCID 53302213tert-Butyl 3-ethenylpyrrolidine-1-carboxylateYield 89.7%

Reagents, catalysts & solvents 3

HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

n-Butyllithium in hexane (44 cm3 of a 1.6 N solution) was added drop-wise to a suspension of 25.5 g (71 mmol) of triphenylmethylphosphonium bromide in 300 cm3 of tetrahydrofuran, which was under argon and cooled to 0° C. The reaction mixture was stirred at 0° C. for 0.5 h and then admixed with a solution of 7.1 g (35.6 mmol) of racemic 3-formylpyrrolidine-1-carboxylic acid tert-butyl ester in 100 cm3 of tetrahydrofuran. After 2.5 hours of reaction at a temperature in the region of 22° C., the mixture was poured into 600 cm3 of saturated aqueous ammonium chloride solution. Following addition of ethyl acetate the organic phase was taken off by decanting, washed twice with water and with saturated sodium chloride solution and then dried over magnesium sulfate and concentrated to dryness under reduced pressure (2.7 kPa). The resulting oil was purified by chromatography on silica gel [eluent: cyclohexane/ethyl acetate (95/5 then 9/1 by volume)]. Concentration of the fractions under reduced pressure (2.7 kPa) gave 6.3 g of racemic 3-vinylpyrrolidine-1-carboxylic acid tert-butyl ester in the form of a colorless oil. Mass spectrum (ES): m/z 198 (MH+), m/z=142.

Workup

  1. customAfter 2.5 hours of reaction at a temperature in the region of 22° C.
  2. customby decanting
  3. washwashed twice with water and with saturated sodium chloride solution
  4. dry with materialdried over magnesium sulfate
  5. concentrationconcentrated to dryness under reduced pressure (2.7 kPa)
  6. customThe resulting oil was purified by chromatography on silica gel [eluent

Sources & evidence

ORD record
ord-7e08ad6461e04781b376d6f3d0f83053
Source dataset
uspto-grants-2006_08
Patent number
US07098331B2

Reaction notes

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