Dimethylformamide → 3-(Benzyloxy)-4-bromophenol

HRID 1155849Notes

Reaction equation

HRID 1155849 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

7

Reactant 4

HCID 6228DimethylformamideHCID 7498Benzyl BromideHCID 811054-BromoresorcinolHCID 82127Potassium hydride

Product 1

HCID 156706543-(Benzyloxy)-4-bromophenol

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 3283Diethyl EtherSolvent

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

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

Sources & evidence

ORD record
ord-4d1d148bfbd64a9fab025ec9e04725dc
Source dataset
uspto-grants-1982_06
Patent number
US04332942

Reaction notes

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