Carbon tetrabromide → Tert-butyl (5-bromopentan-2-yl)carbamate

HRID 474243Notes

Reaction equation

HRID 474243 reaction equation
O[CH2:2][CH2:3][CH2:4][CH:5]([NH:7][C:8](=[O:14])[O:9][C:10]([CH3:13])([CH3:12])[CH3:11])[CH3:6].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C(Br)(Br)(Br)[Br:35]>ClCCl>[Br:35][CH2:2][CH2:3][CH2:4][CH:5]([NH:7][C:8](=[O:14])[O:9][C:10]([CH3:13])([CH3:12])[CH3:11])[CH3:6]

Participants

5

Reactant 3

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 545709tert-butyl N-(5-hydroxypentan-2-yl)carbamate

Product 1

HCID 86668104Tert-butyl (5-bromopentan-2-yl)carbamateYield 53%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To an ice-cold solution of tert-butyl (5-hydroxypentan-2-yl)carbamate (3.6 g, 17.71 mmol) in dichloromethane (150 mL) was added triphenylphosphine (6.97 g, 26.6 mmol) followed by carbon tetrabromide (8.81 g, 26.6 mmol). The reaction mixture was stirred at room temperature for 18 h while monitoring by TLC. The solvent was removed under reduced pressure and the residue was purified by column chromatography (60-120 mesh silica) using 2-5% ethyl acetate in pet-ether to give tert-butyl (5-bromopentan-2-yl)carbamate (2.5 g, 53%) as a light brown liquid. 1H NMR: (400 MHz, CDCl3) δ ppm 4.29 (1H, br s), 3.68 (1H, br s), 3.42 (2H, t, J=6.8 Hz), 1.94-1.86 (2H, m), 1.59-1.46 (2H, m), 1.44 (9H, s), 1.13 (3H, d, J=6.4 Hz).

Workup

  1. customThe solvent was removed under reduced pressure
  2. customthe residue was purified by column chromatography (60-120 mesh silica)

Sources & evidence

ORD record
ord-b541ef29b4274267b2d25d414c5ddd61
Source dataset
uspto-grants-2014_01
Patent number
US08637523B2

Reaction notes

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