Ethanol → Benzocaine

HRID 989484Notes

Reaction equation

HRID 989484 reaction equation
[NH2:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][CH:3]=1.[CH2:11](O)[CH3:12]>>[CH2:11]([O:7][C:6](=[O:8])[C:5]1[CH:9]=[CH:10][C:2]([NH2:1])=[CH:3][CH:4]=1)[CH3:12]

Participants

3

Reactant 2

HCID 702EthanolHCID 9784-Aminobenzoic Acid

Product 1

HCID 2337Benzocaine

Procedure

4-Aminobenzoic acid (5.0 g, 36.46 mmol) in 500 mL 3-neck round bottomed flask, fitted with a condenser, thermometer, addition funnel, stir bar, and nitrogen atmosphere, was dissolved in ethanol (100 mL). Next ethanol/HCl saturate (from bubbling concentrated HCl through ethanol) was added dropwise, by addition funnel. Then stirred at reflux for 1 h, cooled to room temperature, and stirred an additional 104 hours. Reaction mixture was then concentrated under reduced vacuum, and dissolved in ethyl acetate, and washed with water (2×50 mL), dried (K2CO3), filtered and concentrated under reduced vacuum, yielding 3.56 g of an off-white solid. This material was purified by silica gel chromatography, using a Waters HPLC Prep 2000, over one Prep-Pak, in a 1:1 hexanes:ethyl acetate solvent system, yielding the title compound as 2.35 g (39%) as a white solid.

Workup

  1. additionthermometer, addition funnel
  2. concentrationNext ethanol/HCl saturate
  3. custom(from bubbling concentrated HCl through ethanol)
  4. additionwas added dropwise, by addition funnel
  5. stirringThen stirred
  6. temperatureat reflux for 1 h
  7. stirringstirred an additional 104 hours
  8. customReaction mixture
  9. concentrationwas then concentrated under reduced vacuum
  10. dissolutiondissolved in ethyl acetate
  11. washwashed with water (2×50 mL)
  12. dry with materialdried (K2CO3)
  13. filtrationfiltered
  14. concentrationconcentrated under reduced vacuum

Sources & evidence

ORD record
ord-a670ce83a2a84b7e916f30530b39539a
Source dataset
uspto-grants-2003_10
Patent number
US06639107B1

Reaction notes

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