ethyl (2Z)-2-methoxyimino-3-oxo-butanoate synthesis

Yield:60846-14-2 98%

Reaction Conditions:

with potassium carbonate in acetone at 0 - 20; for 5 h;

Steps:

2.3 Synthesis of β-keto-α-alkyloximino esters (1b-1f) and amide (4b)

General procedure: Ethyl 2-methoxyimino-3-oxobutanote (1b): To a stirred solution of 1a (2.0 g, 12.6 mmol) and dimethyl sulfate (1.43 mL, 15.1 mmol) in acetone (20 mL), K₂CO₃ (1.04g, 7.56 mmol) was added slowly at 0°C. The reaction mixture was stirred at room temperature for 5h. After completion of the reaction, monitored by TLC, the reaction mixture was filtered and the filtrate was concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (n-hexane/EtOAc=20:1) to afford the desired product 1b (2.18 g, 98% yield). ¹H NMR (300MHz, CDCl₃) δ: 4.35 (q, J=7.14Hz, 2H), 4.10 (s, 3H), 2.40 (s, 3H), 1.33 (t, J=7.14Hz, 3H) ppm. ¹³C NMR (75MHz, CDCl₃) δ: 193.2, 161.5, 150.4, 64.7, 62.5, 25.5, 14.4 ppm. MS (EI): m/z 173 [M⁺]. TLC: R_f 0.31 (n-hexane/EtOAc 20:1).

References:

Mo, Kilwoong;Park, Jin Hyeong;Kang, Soon Bang;Kim, Youseung;Lee, Yong Sup;Lee, Jae Wook;Keum, Gyochang [Journal of Molecular Catalysis B: Enzymatic,2016,vol. 123,p. 29 - 34]