Ethyl chloroformate → 1-Ethoxycarbonyl-4-ethynyl-4-(4-fluoro-2-nitrophenoxy)piperidine

Participants

Reaction Steps

A suspension of 223 g of N-methyl-4-ethynyl-4-(4-fluoro-2-nitrophenoxy)piperidine, 2 l of dry benzene, 165 g of anhydrous potassium carbonate and 130.3 g of ethyl chloroformate was stirred at reflux for 18 hr under nitrogen. The mixture was filtered and the solvent evaporated. The residue was dissolved in ether, washed with hydrochloric acid, saturated sodium bicarbonate solution, water and saturated sodium chloride solution. The ether solution was dried over anhydrous sodium sulfate and filtered. Evaporation of solvent provided an oil, which was dried at 50°-55° (1 mm). The oil crystallized to provide 226 g (83.8%) of product, mp 56°-68°.

Provenance & Evidence