1-Bromopropane → 3-propoxybenzoic acid

HRID 1258978Notes

Reaction equation

HRID 1258978 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]([CH:10]=[CH:11][CH:12]=1)[C:5]([O:7]CC)=[O:6].[CH2:13](Br)[CH2:14][CH3:15].C(=O)([O-])[O-].[K+].[K+].[OH-].[Na+]>CC(=O)CC.CCO>[CH2:13]([O:1][C:2]1[CH:3]=[C:4]([CH:10]=[CH:11][CH:12]=1)[C:5]([OH:7])=[O:6])[CH2:14][CH3:15]

Participants

7

Reactant 4

HCID 78401-BromopropaneHCID 11430Potassium CarbonateHCID 14798Sodium HydroxideHCID 24522Ethyl 3-hydroxybenzoate

Product 1

HCID 5867993-propoxybenzoic acid

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 6569Methyl Ethyl KetoneSolvent

Conditions

Temperature
25 °C

Procedure

Under N2, the mixture of ethyl 3-hydroxybenzoate (4.16 g, 25 mmol), propyl bromide (4.31 g, 3.2 ml, 35 mmol) and potassium carbonate (4.15 g, 30 mmol) in dry 2-butanone (100 ml) was heated to reflux for 48 h. After the reaction mixture cooled down to 25° C., the suspended inorganic salt was removed by filtration. The concentration of the resulting solution by rotary evaporation yielded pale yellowish syrup, which was then mixed with 2N NaOH (18 ml, 36 mmol) and EtOH (30 ml). After this mixture was stirred for 2 h at 50° C., ethanol was removed at reduced pressure. The aqueous solution was acidified by 6N HCl to pH 2 at 5° C. to generate white precipitate, which was then collected by filtration. The recrystallization of this crude product from hexane/ether yielded pure 3-Propoxy-benzoic acid as colorless crystal (3.77 g, 83.7%). 1H-NMR (400 MHz, d6-DMSO): 7.43 (m, 1 arom. H); 7.34 (m, 2 arom. H); 7.08 (m, 1 arom. H); 3.88 (t, CH3CH2CH2O); 1.65 (m, CH3CH2CH2O); 0.88 (t, CH3CH2CH2O). 13C-NMR (100 MHz, d6-DMSO): 167.12 (—C═O); 158.63; 132.12; 129.68; 121.41; 119.33; 114.41; 69.09; 21.95; 10.32.

Workup

  1. temperaturewas heated
  2. temperatureto reflux for 48 h
  3. customthe suspended inorganic salt was removed by filtration
  4. customThe concentration of the resulting solution by rotary evaporation
  5. customyielded pale yellowish syrup, which
  6. customethanol was removed at reduced pressure
  7. customwas acidified by 6N HCl to pH 2 at 5° C.
  8. filtrationwas then collected by filtration
  9. customThe recrystallization of this crude product from hexane/ether yielded pure 3-Propoxy-benzoic acid as colorless crystal (3.77 g, 83.7%)

Sources & evidence

ORD record
ord-c7908fa84cc449d3aed10170a157630d
Source dataset
uspto-grants-2013_06
Patent number
US08466199B2

Reaction notes

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