Stearic Acid → Methyl 3-oxoicosanoate

HRID 2407050Notes

Reaction equation

HRID 2407050 reaction equation
[C:1](O)(=O)[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17]C.C[C:22]1(C)[O:27][C:26](=[O:28])[CH2:25][C:24](=[O:29])O1.C(N(CC)CC)C.C(P(=O)(OCC)OCC)#N>C(Cl)Cl>[O:29]=[C:24]([CH2:17][CH2:16][CH2:15][CH2:14][CH2:13][CH2:12][CH2:11][CH2:10][CH2:9][CH2:8][CH2:7][CH2:6][CH2:5][CH2:4][CH2:3][CH2:2][CH3:1])[CH2:25][C:26]([O:27][CH3:22])=[O:28]

Participants

6

Reactant 4

HCID 5281Stearic AcidHCID 8471TriethylamineHCID 162492,2-Dimethyl-1,3-dioxane-4,6-dioneHCID 76257Diethyl cyanophosphonate

Product 1

HCID 84502Methyl 3-oxoicosanoate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

Stearic acid (5.0 g, 17.6 mmoles) is suspended in methylene chloride (88 mL) and 2,2-dimethyl-1,3-dioxane-4,6-dione (2.7 g, 18.5 mmoles), triethylamine (6.7 mL, 48.0 mmoles) and diethyl cyanophosphonate (2.7 mL, 17.6 mmoles) are added. All solids dissolve quickly. The solution is stirred for 16 hours at ambient temperature. The reaction mixture is then diluted with methylene chloride (100 mL) and carefully washed three times with aqueous hydrochloric acid (3 M, 50 mL each), three times with water (50 mL each) and once with saturated aqueous sodium chloride (50 mL). The reaction mixture is then dried over anhydrous sodium sulfate, filtered and evaporated. The resulting syrup is dissolved in anhydrous methanol (100 mL) and heated to reflux for 16 hours. The methanol is evaporated and the crude product dissolved in hexanes with slight heating. The crude product was then loaded on silica gel (150 mL bed volume) eluting with hexanes (500 mL) then hexane:acetone (98:2 [v/v], 1000 mL). Fractions containing pure product by thin layer chromatography are pooled and evaporated to dryness. The resulting oil is dried well in vacuo. The yield is 5.2 g (87%).

Workup

  1. dissolutionAll solids dissolve quickly
  2. washcarefully washed three times with aqueous hydrochloric acid (3 M, 50 mL each), three times with water (50 mL each)
  3. dry with materialThe reaction mixture is then dried over anhydrous sodium sulfate
  4. filtrationfiltered
  5. customevaporated
  6. dissolutionThe resulting syrup is dissolved in anhydrous methanol (100 mL)
  7. temperatureheated
  8. temperatureto reflux for 16 hours
  9. customThe methanol is evaporated
  10. dissolutionthe crude product dissolved in hexanes with slight heating
  11. washeluting with hexanes (500 mL)
  12. additionFractions containing pure product by thin layer chromatography
  13. customevaporated to dryness
  14. customThe resulting oil is dried well in vacuo

Sources & evidence

ORD record
ord-81d350cd002140cf9d0f94ef01ad7bdc
Source dataset
uspto-grants-2014_08
Patent number
US08809514B2

Reaction notes

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