2,3-Dihydroxybenzoic Acid → 2-Hydroxy-3-propoxybenzoic acid

HRID 614824Notes

Reaction equation

HRID 614824 reaction equation
[OH:1][C:2]1[C:10]([OH:11])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[CH2:12](I)[CH2:13][CH3:14].[OH-].[K+].C>C(O)C.O>[CH2:12]([O:11][C:10]1[CH:9]=[CH:8][CH:7]=[C:3]([C:4]([OH:6])=[O:5])[C:2]=1[OH:1])[CH2:13][CH3:14]

Participants

7

Reactant 4

HCID 192,3-Dihydroxybenzoic AcidHCID 297MethaneHCID 14797Potassium Hydroxide2×HCID 336431-Iodopropane2×

Product 1

HCID 130269212-Hydroxy-3-propoxybenzoic acidYield 65%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

2,3-Dihydroxybenzoic acid (6.16 g) and propyl iodide (6.8 g) were added to a mixture of aqueous potassium hydroxide solution (20 ml, 25% w/v), water (50 ml) and ethanol (50 ml) and the mixture was stirred and heated at reflux for 5 hours. A further quantity of propyl iodide (17 g) was then added and the mixture was again heated at reflux for 4 hours, small quantities of solid potassium hydroxide being added meanwhile in order to keep the pH at about 10. Decolourizing charcoal was then carefully added, the mixture was filtered hot and the filtrate was acidified to pH 1 by treatment with concentrated hydrochloric acid. The resulting solid was filtered off and dissolved in aqueous ammonia solution (2N), and the solution was treated with decolourizing charcoal, filtered, and the filtrate was acidified to pH 1 by treatment with hydrochloric acid to give 3-propoxysalicylic acid (5.1 g), m.p. 114°-118° C.

Workup

  1. temperatureheated
  2. temperatureat reflux for 5 hours
  3. temperaturethe mixture was again heated
  4. temperatureat reflux for 4 hours
  5. filtrationthe mixture was filtered hot
  6. filtrationThe resulting solid was filtered off
  7. dissolutiondissolved in aqueous ammonia solution (2N)
  8. additionthe solution was treated with decolourizing charcoal
  9. filtrationfiltered

Sources & evidence

ORD record
ord-43fd06c06e06429e97ca6784eacd5062
Source dataset
uspto-grants-1979_03
Patent number
US04146631

Reaction notes

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