Ethanol → Ethyl-2,4-dioxohexanoate
Reaction equation
[H-].[Na+].C(O)C.[CH3:6][C:7](=[O:10])[CH2:8][CH3:9].[C:11]([O:18][CH2:19][CH3:20])(=[O:17])[C:12]([O:14]CC)=O.S(=O)(=O)(O)O>>[O:14]=[C:12]([CH2:6][C:7](=[O:10])[CH2:8][CH3:9])[C:11]([O:18][CH2:19][CH3:20])=[O:17]Participants
Procedure
To a suspension of sodium hydride (44 g, 1.10 mol, 60% in mineral oil) dry ethanol (318 mL, 5.44 mol) was added dropwise at a temperature of 0° C. Ten minutes after the addition was completed and still at 0° C., a mixture of 2-butanone (90 mL, 1.0 mol) and diethyl oxalate (136 mL, 1.0 mol) was added dropwise. The reaction mixture was stirred at rt over night. Then, sulfuric acid was added (4N aq., 550 mL, 1.1 mol). The crude product was extracted into diethyl ether. After washing with water and brine, the organic extract was dried over anhydrous magnesium sulfate, followed by filtration and evaporation of the solvent. The residue was subjected to distillation in vacuo. At a boiling point of 68-78° C. (2.2-2.6 mbar) the product was obtained as a colorless liquid (68.4 g, 40%): 1H NMR (400 MHz, CDCl3) δ 14.40 (broad, 1H), 6.38 (s, 1H), 4.36 (quart, 2H), 2.53 (quart, 2H), 1.38 (t, 3H), 1.17 (t, 3H); DCI(NH3)-MS m/z 173 (MH)+, 190 (M+NH4)+; HPLC RT (Method I) 4.02 min.
Workup
- additionwas added dropwise at a temperature of 0° C
- additionTen minutes after the addition
- customwas completed and still at 0° C.
- additionwas added dropwise
- extractionThe crude product was extracted into diethyl ether
- washAfter washing with water and brine
- extractionthe organic extract
- dry with materialwas dried over anhydrous magnesium sulfate
- filtrationfollowed by filtration and evaporation of the solvent
- distillationThe residue was subjected to distillation in vacuo
Sources & evidence
- ORD record
- ord-7bf7572be97e4fca89a969bdc58619f7
- Source dataset
- uspto-grants-2014_08
- Patent number
- US08796253B2
Reaction notes
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