Dimethylformamide → 3-(Benzyloxy)-4-bromophenol

HRID 26084

Reaction equation

[H-].[K+].CN(C)C=O.[Br:8][C:9]1[CH:15]=[CH:14][C:12]([OH:13])=[CH:11][C:10]=1[OH:16].[CH2:17](Br)[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1>CCOCC.O>[CH2:17]([O:16][C:10]1[CH:11]=[C:12]([OH:13])[CH:14]=[CH:15][C:9]=1[Br:8])[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1

Participants

Conditions

Temperature: 0 °C

Procedure

To a 0° C. slurry of 1.7 g. (42.5 mmoles) of potassium hydride in 35 ml. of N,N-dimethylformamide is slowly added a solution of 7.22 g. (38.2 mmoles) of 4-bromoresorcinol. The resultant mixture is stirred for 30 minutes and then 4.54 ml. (38.2 mmoles) of benzyl bromide is slowly added. The reaction mixture is stirred 3 hours longer at 0° C. and then added to 200 ml. of cold water and 200 ml. of ether. The ether extract is washed twice with 200 ml. portions of water, dried over magnesium sulfate and evaporated to an oil. The crude oil is purified via column chromatography on 400 g. of silica gel eluted with 25% ether-pentane to yield (in order of elution) 2.2 g. (16%) of 2,4-dibenzyloxybromobenzene, 0.21 g. (2%) of 5-benzyloxy-2-bromophenol and 3.52 g. (33%) of 3-benzyloxy-4-bromophenol.

Workup

customTo a 0° C.
additionadded to 200 ml
extractionThe ether extract
washis washed twice with 200 ml
dry with materialportions of water, dried over magnesium sulfate
customevaporated to an oil
customThe crude oil is purified via column chromatography on 400 g
washof silica gel eluted with 25% ether-pentane
customto yield
wash(in order of elution) 2.2 g

Sources & evidence

ORD record: ord-cbaf3fd342894c14a78febb86ca2b7a8
Source dataset: uspto-grants-1979_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04147872

Linked notes

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