Ethanol → 11-ethoxyundecanoic acid

HRID 362756Notes

Reaction equation

HRID 362756 reaction equation
Br[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][C:12]([OH:14])=[O:13].[OH-].[K+].[CH2:17]([OH:19])[CH3:18]>C(OCC)(=O)C>[CH2:17]([O:19][CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][C:12]([OH:14])=[O:13])[CH3:18]

Participants

5

Procedure

11-bromoundecanoic acid (2.25 g, 8.47 mmol) was added to a solution of potassium hydroxide (2.15 g, 38.3 mmol) in absolute ethanol (20 mL) and refluxed for 7 hrs. After cooling and acidification with HCl, solvent was removed under reduced pressure to give a white solid. The sample was dissolved in ethyl acetate and extracted with water. The organic phase was dried over sodium sulfate, and the solvent was removed under reduced pressure. The product was purified by silica column chromatography in 1% diethyl ether/0.3% formic acid/methylene chloride. Solvent was removed under reduced pressure to yield 11-(ethoxy)undecanoic acid (680 mg, 35%): mp 44°-45.5° C.; 1H NMR (300 MHz, CDCl3) δ 1.20 (t, 3H, J=7.0, CH3), 1.24-1.40 (bm, 12H, methylene envelope), 1.52-1.68 (bm, 4H, O--CH2 --CH2 ; CH2 --CH2 --COOH), 2.34 (t, 2H, J=7.5, CH2 --COOH), 3.41 (t, 2H, J=6.8, 0--CH2 --CH2), 3.48 (g, 2H, J=7.0, 0--CH2 --CH3), 10.25 (br, 1H, COOH); 13C NMR (75.4 MHz, CDCL3) δ 15.27, 24.75, 26.23, 29.11, 29.26, 29.40, 29.55*, 29.80, 34.12, 66.06, 70.76, 179.71; m/z 231 (M+H+).

Workup

  1. temperaturerefluxed for 7 hrs
  2. temperatureAfter cooling
  3. customacidification with HCl, solvent was removed under reduced pressure
  4. customto give a white solid
  5. extractionextracted with water
  6. dry with materialThe organic phase was dried over sodium sulfate
  7. customthe solvent was removed under reduced pressure
  8. customThe product was purified by silica column chromatography in 1% diethyl ether/0.3% formic acid/methylene chloride
  9. customSolvent was removed under reduced pressure

Sources & evidence

ORD record
ord-04bd0c627cf54509a7301aa9e43752a5
Source dataset
uspto-grants-1999_02
Patent number
US05871954

Reaction notes

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