Ethyl 2,4-dioxovalerate → Ethyl 5-methylisoxazole-3-carboxylate

Temperature

80 °C

To a 100 mL RB flask fitted with a condenser and a magnetic stirrer was charged with 10.5 mL of ethanol. To the stirred solvent were added ethyl 2,4-dioxopentanoate (2.5 g, 15 mmol), hydroxylamine hydrochloride (1.09 g, 15 mmol) and sodium bicarbonate (1.32 g, 15 mmol). After addition, the reaction mixture was refluxed at 80° C. for 8 h under nitrogen atmosphere. After completion of the reaction, the solvent was evaporated from the reaction mixture. Ethyl acetate (50 mL) was added; organic layer was washed with water (50 mL), followed by brine solution (25 mL). The organic layer was dried over anhydrous Na2SO4 and the solvent was removed under reduced pressure. The product was obtained as a colorless liquid (1 g, yield: 40.08%). 1H NMR (300 MHz, CDCl3): δ 6.34 (s, 1H), 4.33-4.40 (q, 2H), 2.43 (s, 3H), 1.32-1.37 (t, 3H).

1. customTo a 100 mL RB flask fitted with a condenser and a magnetic stirrer
2. additionAfter addition
3. customAfter completion of the reaction
4. customthe solvent was evaporated from the reaction mixture
5. additionEthyl acetate (50 mL) was added
6. washorganic layer was washed with water (50 mL)
7. dry with materialThe organic layer was dried over anhydrous Na2SO4
8. customthe solvent was removed under reduced pressure

ORD record

ord-64a2c30ef88848648759264c452e9384

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09278915B2