Carbon tetrabromide → (S)-N-Boc-2-ethynylpyrrolidine

HRID 2212131Notes

Reaction equation

HRID 2212131 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:12][CH2:11][CH2:10][C@H:9]1[CH:13]=O)=[O:7])([CH3:4])([CH3:3])[CH3:2].[C:15](Br)(Br)(Br)Br.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C(Cl)Cl>[C:1]([O:5][C:6]([N:8]1[CH2:12][CH2:11][CH2:10][C@H:9]1[C:13]#[CH:15])=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 3

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

Product 1

HCID 11030701(S)-N-Boc-2-ethynylpyrrolidine

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A solution of (2S)-N-(tert-butoxycarbonyl)-2-formylpyrrolidine (4.0 g, 20 mmole), carbon tetrabromide (6.67 g, 20.1 mmole) and triphenylphosphine (5.26 g, 20.1 mmole) in methylene chloride (100 mL) was stirred at ambient temperature under a nitrogen atmosphere for 24 hours. The mixture was concentrated, then purified by chromatography, using (1:1) ethyl acetate:hexane as eluant to provide the desired product as an oil. The product was dissolved in dry tetrahydrofuran (50 mL) and cooled to −78° C. A solution of n-butyllithium (50.25 mL, 20.1 mmole, 2.5 M solution in hexanes) was added and the mixture was stirred at −78° C. for 1 h. The material was quenched with water (20 mL) and extracted with ethyl acetate (3×50 mL). The combined extracts were dried (K2CO3), concentrated and purified by chromatography, using (1:1) ethyl acetate:hexane as eluant to provide (3.10 g, 91%) of a colorless oil.

Workup

  1. concentrationThe mixture was concentrated
  2. custompurified by chromatography

Sources & evidence

ORD record
ord-19af09b9e21f41f59730471d1ef5b5e0
Source dataset
uspto-grants-2006_09
Patent number
US07101896B2

Reaction notes

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