Sodium borohydride → 2-(4-Bromophenyl)pyrrolidine

HRID 908025Notes

Reaction equation

HRID 908025 reaction equation
[BH4-].[Na+].[Br:3][C:4]1[CH:9]=[CH:8][C:7]([C:10]2[CH2:11][CH2:12][CH2:13][N:14]=2)=[CH:6][CH:5]=1>O.CO>[Br:3][C:4]1[CH:5]=[CH:6][C:7]([CH:10]2[CH2:11][CH2:12][CH2:13][NH:14]2)=[CH:8][CH:9]=1

Participants

4

Reactant 2

HCID 4311764Sodium borohydrideHCID 114246115-(4-Bromophenyl)-3,4-dihydro-2h-pyrrole

Product 1

HCID 42814942-(4-Bromophenyl)pyrrolidineYield 84%

Reagents, catalysts & solvents 1

HCID 22242641Methanol--water (1/1)Solvent

Procedure

NaBH4 (1.52 g, 40 mmol) was added to a solution of 5-(4-bromophenyl)-3,4-dihydro-2H-pyrrole (4.48 g, 20 mmol) in H2O/MeOH (30 mL, v/v 1:4) at −41° C. After stirred for 4 hrs, the solution was allowed to warm to room temperature. Once the reaction was deemed complete by TLC, the unreacted NaBH4 was quenched by the addition of 2 N HCl. The solution was then diluted with water and ether, and separated two layers. The aqueous layer was washed with an additional portion of ether, basified with 4 M NaOH (pH 12-13) and washed with ethyl acetate. The combined organic extracts were washed with brine, and then dried over Na2SO4. Evaporation of the solvent afforded the title crude product as a yellow oil (3.8 g, yield 84%), which was used directly in the next step. LC-MS (ESI) m/z: 226 (M+1)+.

Workup

  1. customthe unreacted NaBH4 was quenched by the addition of 2 N HCl
  2. additionThe solution was then diluted with water and ether
  3. customseparated two layers
  4. washThe aqueous layer was washed with an additional portion of ether
  5. washwashed with ethyl acetate
  6. washThe combined organic extracts were washed with brine
  7. dry with materialdried over Na2SO4
  8. customEvaporation of the solvent

Sources & evidence

ORD record
ord-09680d18044e4e4b994223005cce20e3
Source dataset
uspto-grants-2011_09
Patent number
US08012976B2

Reaction notes

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