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ChemicalBook CAS DataBase List ethyl 1-acetylcyclopropanecarboxylate
32933-03-2

ethyl 1-acetylcyclopropanecarboxylate synthesis

8synthesis methods
Ethyl acetoacetate

141-97-9

1,2-Dibromoethane

106-93-4

ethyl 1-acetylcyclopropanecarboxylate

32933-03-2

Step 1) Synthesis of ethyl 1-acetylcyclopropanecarboxylate: To a solution of ethyl 3-oxobutanoate (26 g, 200 mmol) in acetone (500 mL) was added potassium carbonate (82.8 g, 600 mmol) followed by 1,2-dibromoethane (45.12 g, 240 mmol). The reaction mixture was refluxed for 24 hours. After completion of the reaction, the mixture was filtered and the filtrate was concentrated under vacuum. The residue was purified by silica gel column chromatography with an eluent ratio of 1:50 (v/v) ethyl acetate/hexane to afford the target compound ethyl 1-acetylcyclopropanecarboxylate as a colorless oil (18.7 g, 60% yield). Mass spectrum (ESI, cation mode) m/z: 157 (M+1); 1H NMR (400 MHz, CDCl3) δ: 1.25-1.29 (t, J=7.2 Hz, 3H), 1.45 (s, 4H), 2.45 (s, 3H), 4.18-4.20 (q, 2H).

-

Yield:32933-03-2 78.1 g (65.1%)

Reaction Conditions:

with potassium carbonate in acetone;

Steps:

R.11.1 Ethyl 1-acetylcyclopropanecarboxylate

Referential Example 11-1 Ethyl 1-acetylcyclopropanecarboxylate Ethyl acetoacetate (100 g, 0.77 mol) was dissolved in acetone (500 ml). To the thus obtained solution was added dibromoethane (361 g, 1.92 mol) and potassium carbonate (266 g, 1.92 mol) and the mixture was heated under reflux for 4 days. After filtering off insoluble matter, the filtrate was distilled under reduced pressure (80° C./8 mmHg) to obtain 78.1 g (65.1%) of the title compound as a colorless oily substance. 1 H-NMR (400 MHz, CDCl3) δ: 1.29 (3H, t, J=7.33 Hz), 1.47 (4H, s), 2.47 (3H, s), 4.21 (2H, q, J=7.33 Hz).

References:

US6121285,2000,A

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