Benzyl Bromide → Hexaethylene Glycol Monobenzyl Ether

HRID 276801Notes

Reaction equation

[CH2:1]([OH:19])[CH2:2][O:3][CH2:4][CH2:5][O:6][CH2:7][CH2:8][O:9][CH2:10][CH2:11][O:12][CH2:13][CH2:14][O:15][CH2:16][CH2:17][OH:18].[CH2:20](Br)[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1>[OH-].[Na+].O>[CH2:20]([O:18][CH2:17][CH2:16][O:15][CH2:14][CH2:13][O:12][CH2:11][CH2:10][O:9][CH2:8][CH2:7][O:6][CH2:5][CH2:4][O:3][CH2:2][CH2:1][OH:19])[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1

Participants

Conditions

Temperature: 100 °C

Procedure

A mixture of hexaethylene glycol (Aldrich, 100 g) and benzyl bromide (Aldrich, 12 g) in aqueous sodium hydroxide (50% (w/w), 80 ml) was stirred at 100° C. (oil bath) under nitrogen for 2 h. The reaction mixture was then cooled to ambient temperature, diluted with water to a total volume of 500 ml, and extracted with diethyl ether (200 ml) to remove dibenzylated product. Sodium chloride (100 g) was added to the aqueous layer, which was extracted further with diethyl ether (6×100 ml). These ether extracts were combined, dried (sodium sulfate), and concentrated to give hexaethylene glycol monobenzyl ether as an oil (25 g, 20% based on glycol), 1H-NMR (CDCl3) δ: 7.30 (m, 5, 5 phenyl CH), 4.53 (s, 2, benzyl CH2), 3.69-3.54 (m, 22, 11 OCH2), 3.06 (br s, 3, OH and CH2O).

Workup

temperatureThe reaction mixture was then cooled to ambient temperature
extractionextracted with diethyl ether (200 ml)
customto remove dibenzylated product
additionSodium chloride (100 g) was added to the aqueous layer, which
extractionwas extracted further with diethyl ether (6×100 ml)
dry with materialdried (sodium sulfate)
concentrationconcentrated

Sources & evidence

ORD record: ord-5599a1384c3c4f5b85557603cd7cc4a5
Source dataset: uspto-grants-2002_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06355646B1

Reaction notes

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