Acetone → Ethyl 2,4-dioxovalerate

To a 100 mL two neck RB flask fitted with magnetic stirrer was charged with 25 mL of ethanol. To the stirred solvent was added sodium metal pieces (0.86 g, 37 mmol) slowly at 0° C. under nitrogen atmosphere and stirred for 30 minutes at room temperature. After 30 minutes, diethyl oxalate (5 g, 34.2 mmol) in acetone (10 mL) was added drop wise. During addition, the reaction mixture was changed to yellow color. After addition, thick mass was observed, was added ethanol (10 mL) to the reaction mixture and stirred at room temperature for 1 h. Then, the reaction mixture was filtered; the solids were dissolved in ice-cold water (50 mL), acidified with concentrated sulfuric acid and extracted with ethyl acetate (100 mL). The organic layer was concentrated under reduced pressure and the solvent traces were removed by triturated with n-hexane. The product was obtained as brown liquid (3.2 g, yield: 59.2%). 1H NMR (300 MHz, DMSO-d6): δ 5.46 (s, 2H), 4.02-4.09 (q, 2H), 1.89 (s, 3H), 1.18-1.22 (t, 3H).

1. waitAfter 30 minutes
2. additionDuring addition
3. additionAfter addition, thick mass
4. stirringstirred at room temperature for 1 h
5. filtrationThen, the reaction mixture was filtered
6. dissolutionthe solids were dissolved in ice-cold water (50 mL)
7. extractionextracted with ethyl acetate (100 mL)
8. concentrationThe organic layer was concentrated under reduced pressure
9. customthe solvent traces were removed
10. customby triturated with n-hexane

ORD record

ord-2fdea418de0f405889ceead3fab54a60

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09278915B2