Hydrochloric Acid → 2,4-Bis(benzyloxy)-5-bromobenzoic acid

HRID 644595Notes

Reaction equation

HRID 644595 reaction equation
[OH:1][C:2]1[CH:10]=[C:9]([OH:11])[C:8]([Br:12])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].C(=O)([O-])[O-].[K+].[K+].[CH2:19](Br)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1.[OH-].[K+].Cl>CN(C=O)C.O.CO>[CH2:19]([O:1][C:2]1[CH:10]=[C:9]([O:11][CH2:4][C:3]2[CH:7]=[CH:8][CH:9]=[CH:10][CH:2]=2)[C:8]([Br:12])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5])[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1

Participants

9

Reactant 5

HCID 313Hydrochloric AcidHCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 14797Potassium HydroxideHCID 818145-Bromo-2,4-dihydroxybenzoic acid

Product 1

HCID 469156382,4-Bis(benzyloxy)-5-bromobenzoic acidYield 56%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

2,4-dihydroxy-5-bromobenzoic acid (5.16 g, 22.15 mmol) was dissolved in DMF (40 ml) and potassium carbonate (12.2 g) and benzyl bromide (8 ml) were sequentially added. The mixture was stirred at room temperature for 18 hours under nitrogen. An aqueous solution of potassium hydroxide (2 g) in water (25 ml) was then added, followed by methanol (50 ml) and the mixture heated to reflux with vigorous stirring for 24 hours. The mixture was then allowed to cool, was poured into 1N HCl (250 ml) and was then extracted with ether and then DCM. The combined organic layers were dried over magnesium sulphate and the solvent evaporated in vacuo. The resulting solid material was washed with P.E. and then Et2O (3×50 ml) to yield pure product (5.2 g, 56%). 1H NMR (MeOH-d4) 8.06 (1H, s), 7.51-7.30 (10H, m), 6.85 (1H, s), 5.22 (2H, s), 5.20 (2H, s). MS: [M+H]+ 413.

Workup

  1. temperaturethe mixture heated
  2. temperatureto reflux
  3. stirringwith vigorous stirring for 24 hours
  4. temperatureto cool
  5. extractionwas then extracted with ether
  6. dry with materialThe combined organic layers were dried over magnesium sulphate
  7. customthe solvent evaporated in vacuo
  8. washThe resulting solid material was washed with P.E

Sources & evidence

ORD record
ord-08517741160d4bbbba56703880577fa6
Source dataset
uspto-grants-2010_04
Patent number
US07700625B2

Reaction notes

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