Ethyl2-cyano-3-ethyl-2-pentenoate synthesis

Yield:868-04-2 86%

Reaction Conditions:

with ammonium acetate;glacial acetic acidDean-Stark;Reflux;Inert atmosphere;Reagent/catalyst;

Steps:

60.1; 74.1 Step 1

To a 500 ml three-neck flask bottom was added 200 ml toluene, 3-pentanone (20 g, 232 mmol, 1.0 eq), ethyl cyanoacetate (36.79 g, 325 mmol, 1.4 eq), ammonium acetate (4.78 g, 58 mmol, 0.25 eq), acetic acid (16.74 g, 279 mmol, 1.2 eq). The flask was equipped with a Dean-Stark tube. The solution was refluxed under N2 overnight. GC showed the solution was nearly complete. The solution was cooled and 300 ml MTBE was added. The organic phase was washed with water (75 ml*2), dried over Na₂SO₄ and concentrated under vacuum. The residure was distilled under 0.2 torr to afford 60A (35 g) as a colorless liquid. Another 62 g 3-pentanone was used to make compound 60A and 100 g of 60A as a colorless liquid was obtained. Yield=86%.

References:

WO2022/76383,2022,A1 Location in patent:Paragraph 00383; 00418