Pyridine → HCID 73887173, compound

Participants

Reaction Conditions

Reaction Steps

To a cooled (0° C.) solution of 2,2-difluoropropionic acid (prepared according to the procedure described in U.S. Pat. No. 5,859,051) (2.20 g, 20.0 mmol) in dichloromethane (15 ml) was added oxalyl chloride (2.79, 22.0 mmol) dropwise over 10 min. The mixture was stirred at 0° C. for 10 min then allowed to warm to ambient temperature overnight. The mixture was cooled to −10° C. and added via a cannula to a cooled (−10° C.) solution of ethyl vinyl ether (1.59 g, 22.0 mmol) and pyridine (1.74 g, 22.0 mmol) in dichloromethane (50 ml). The mixture was stirred at −10° C. for 10 min then at ambient temperature for 5 h. The brown solution was diluted with dichloromethane (30 ml) and washed with ice-cold 1M sulphuric acid (2×50 ml) and ice-cold water (2×50 ml), dried over anhydrous sodium sulfate and evaporated to give crude 1-ethoxy-4,4-difluoropent-1-en-3-one (3.28 g, 100%) as an orange oil: δH (400 MHz, CDCl3) 1.38 (3H, t, J 7), 1.71 (3H, t, J 19), 4.05 (2H, q, J 7), 5.94 (1H, dt, J 12 and 1), 7.81 (1H, d, J 12).

Provenance & Evidence