Benzoic Acid → 3-(Benzyloxy)-2,6-dichlorobenzoic acid

HRID 1154009Notes

Reaction equation

HRID 1154009 reaction equation
[Cl:1][C:2]1[C:10]([OH:11])=[CH:9][CH:8]=[C:7]([Cl:12])[C:3]=1[C:4]([OH:6])=[O:5].[OH-].[Na+].[C:15](O)(=O)[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.C(Cl)C1C=CC=CC=1>C(O)C.C1(C)C=CC=CC=1>[CH2:15]([O:11][C:10]1[C:2]([Cl:1])=[C:3]([C:7]([Cl:12])=[CH:8][CH:9]=1)[C:4]([OH:6])=[O:5])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

7

Reactant 4

HCID 243Benzoic AcidHCID 7503Benzyl Chloride2×HCID 14798Sodium Hydroxide4×HCID 133699772,6-Dichloro-3-hydroxybenzoic acid

Product 1

HCID 151832873-(Benzyloxy)-2,6-dichlorobenzoic acid

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 1140TolueneSolvent

Procedure

271.6 g of 2,6-dichloro-3-hydroxybenzoic acid are dissolved in ethanol (2 l). Aqueous sodium hydroxide (242 g of 50% aqueous NaOH solution in 550 ml H2O) is added to the benzoic acid solution, followed by the addition of benzyl chloride (368 g). The reaction mixture is heated to reflux with stirring, and after one hour, additional sodium hydroxide solution (45 g of a 50% aqueous NaOH) and benzyl chloride (30 g) are added. After one hour twenty-five minutes, another 20 g of 50% sodium hydroxide solution are added. After twenty minutes, the reaction mixture is cooled and evaporated to remove ethanol. The mixture is then partitioned between diethylether (2 l) and 5% aqueous sodium hydroxide (2 l). The layers are separated and the aqueous solution washed with diethylether. The aqueous extract is cooled in an ice bath and acidified just short of neutral with conc. HCl. Diethylether (2 l) is added and the solution made strongly acidic. The two layers are stirred for fifteen minutes and separated. The aqueous layer is washed with diethylether and the combined ether layers washed with H2O, saturated sodium chloride solution, and dried over Na2SO4. The ether is filtered and the filtrate evaporated in vacuo to a light yellow oil (338.2 g). 500 ml of toluene are added to the oil and partially evaporated, resulting in a precipitate. The suspension is allowed to stand and used without further treatment for the further reactions. The toluene suspension contains a large amount of heavy crystalline precipitate.

Workup

  1. temperatureThe reaction mixture is heated
  2. temperatureto reflux
  3. waitAfter one hour twenty-five minutes
  4. waitAfter twenty minutes
  5. temperaturethe reaction mixture is cooled
  6. customevaporated
  7. customto remove ethanol
  8. customThe mixture is then partitioned between diethylether (2 l) and 5% aqueous sodium hydroxide (2 l)
  9. customThe layers are separated
  10. washthe aqueous solution washed with diethylether
  11. extractionThe aqueous extract
  12. temperatureis cooled in an ice bath
  13. additionDiethylether (2 l) is added
  14. stirringThe two layers are stirred for fifteen minutes
  15. customseparated
  16. washThe aqueous layer is washed with diethylether
  17. washthe combined ether layers washed with H2O, saturated sodium chloride solution
  18. dry with materialdried over Na2SO4
  19. filtrationThe ether is filtered
  20. customthe filtrate evaporated in vacuo to a light yellow oil (338.2 g)
  21. addition500 ml of toluene are added to the oil
  22. custompartially evaporated
  23. customresulting in a precipitate

Sources & evidence

ORD record
ord-16f0d266521049b09dee3e5dd7335bee
Source dataset
uspto-grants-1984_12
Patent number
US04487779

Reaction notes

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