1-Octanol → Pentanoic acid, 5-(octyloxy)-

HRID 619760Notes

Reaction equation

HRID 619760 reaction equation
Br[CH2:2][CH2:3][CH2:4][CH2:5][C:6]([OH:8])=[O:7].[OH-].[K+].[CH2:11]([OH:19])[CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH3:18]>>[CH2:11]([O:19][CH2:2][CH2:3][CH2:4][CH2:5][C:6]([OH:8])=[O:7])[CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH3:18]

Participants

4

Conditions

Temperature
97 °C

Procedure

5-bromopentanoic acid (2 g, 11.0 mmol) was added to a solution of potassium hydroxide (2.48 g, 44.2 mmol) in 1-octanol (20 mL) and stirred at 97° C. for 27 hrs. After cooling, the product was extracted at pH=1 with ethyl acetate and water. The organic phase was dried over sodium sulfate and solvent was removed. 1-octanol was removed by short path (Kugelrohr) distillation (50-70° C., 0.5 mm Hg). To ensure complete cleavage of the octyl ester, the residue was stirred 3 hrs with methanol/water/KOH (50%/50%/2.5 g, 40 mL) at 25° C. 1-octanol was extracted into ethyl acetate at pH=12 . 5-(octyloxy)pentanoic acid was extracted from the aqueous phase into ethyl acetate after adjusting the pH to 1.5 with HCl. After drying over sodium sulfate, the solvent was removed at reduced pressure. Silica column chromatography in 10% ethyl acetate/hexane/0.3% formic acid, yielded 5-(octyloxy)pentanoic acid (235 mg, 9%): mp <30° C.; 1H NMR (300 MHz, CDCl3) δ0.88 (t, 3H, J=6.6), 1.18-1.39 (bm, 10H, methylene envelope), 1.48-1.77 (bm, 6H, CH2CH2OCH2CH2, CH2CH2COOH), 2.39 (t, 2H, J=7.1, CH2COOH), 3.34-3.49 (bm, 4H, CH2OCH2), 10.66 (br, 1H, COOH); 13C NMR (75.4 MHz, CDCl3) 14.18, 21.59, 22.73, 26.22, 29.03, 29.32, 29.51, 29.72, 31.89, 33.85, 70.22, 71.07, 179.55; m/z 231 (M+H).

Workup

  1. temperatureAfter cooling
  2. extractionthe product was extracted at pH=1 with ethyl acetate and water
  3. dry with materialThe organic phase was dried over sodium sulfate and solvent
  4. customwas removed
  5. custom1-octanol was removed by short path (Kugelrohr) distillation (50-70° C., 0.5 mm Hg)
  6. stirringthe residue was stirred 3 hrs with methanol/water/KOH (50%/50%/2.5 g, 40 mL) at 25° C
  7. extraction1-octanol was extracted into ethyl acetate at pH=12
  8. extraction5-(octyloxy)pentanoic acid was extracted from the aqueous phase into ethyl acetate
  9. dry with materialAfter drying over sodium sulfate
  10. customthe solvent was removed at reduced pressure

Sources & evidence

ORD record
ord-d05e7073f7f8459cb098b92c07ac0f42
Source dataset
uspto-grants-1999_09
Patent number
US05959145

Reaction notes

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