Hydrochloric Acid → Ethyl 4-cyclopropyl-2,4-dioxobutanoate

Participants

Reaction Steps

Sodium metal (2.411 g, 105 mmol) was dissolved in ethanol (50 mL). The solution was heated to reflux followed by addition of a mixture of 1-cyclopropylethanone (8.4 g, 100 mmol) and diethyl oxalate (14.59 g, 100 mmol) dropwise over 30 minutes. The reaction mixture was heated at reflux for an additional 2 h, and then allowed to cool to room temperature over a 2 d period. The contents were diluted with water (200 mL) and acidified by dropwise addition of 6N HCl. The contents were extracted with EtOAc (3×75 mL), washed with water, brine, dried over MgSO4, filtered, and concentrated in vacuo. The final product was collected as 14.3 g (74%). LCMS E-S (M+H)=184.8 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.03 (d, J=7.83 Hz, 2H) 1.13-1.19 (m, 2H) 1.31 (t, J=7.07 Hz, 3H) 1.81-1.90 (m, 1H) 4.29 (q, J=7.16 Hz, 2H) 6.43 (s, 1H).

Provenance & Evidence