Pyridine → Methyl 3-oxoicosanoate

HRID 257106Notes

Reaction equation

HRID 257106 reaction equation
[C:1](Cl)(=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:29][C:27](=[O:28])[CH2:26][C:24](=[O:25])O1.N1C=CC=CC=1>C(Cl)Cl>[O:25]=[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])[CH2:26][C:27]([O:29][CH3:22])=[O:28]

Participants

5

Reactant 3

HCID 1049PyridineHCID 8212Stearoyl chlorideHCID 162492,2-Dimethyl-1,3-dioxane-4,6-dione

Product 1

HCID 84502Methyl 3-oxoicosanoate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

270 ml of stearoyl chloride were added dropwise at a maximum of 150° C. to a solution of 117 g of Meldrum's acid and 131 ml of pyridine in 1.5 I of methylene chloride. After stirring the reaction mixture was washed with 4N hydrochloric acid, the aqueous phase was back-extracted with methylene chloride and the methylene chloride phase was dried and concentrated. The residue was taken up in methanol and stirred under reflux. After cooling the separated crystals were filtered off, dissolved in methylene chloride and chromatographed on silica gel with methylene chloride. There were obtained 175 g of methyl 3-oxoeicosanoate, m.p. 52°-54° C.

Workup

  1. washwas washed with 4N hydrochloric acid
  2. extractionthe aqueous phase was back-extracted with methylene chloride
  3. dry with materialthe methylene chloride phase was dried
  4. concentrationconcentrated
  5. stirringstirred
  6. temperatureunder reflux
  7. temperatureAfter cooling the separated crystals
  8. filtrationwere filtered off
  9. dissolutiondissolved in methylene chloride
  10. customchromatographed on silica gel with methylene chloride

Sources & evidence

ORD record
ord-03979860f138403b88e7e955a35ff59d
Source dataset
uspto-grants-1993_11
Patent number
US05260310

Reaction notes

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