Ethyl chloroformate → 4-Ethoxycarbonyl-1-(2-pyrrolidone-5-carbonyl)piperazine

Participants

Reaction Steps

A mixed solution of 2.1 g of 1-(2-pyrrolidone-5-carbonyl)piperazine, 2.5 g of anhydrous potassium carbonate and 120 ml of acetonitrile was cooled with ice water and 1.1 g of ethyl chlorocarbonate in 10 ml of acetonitrile was dropped therein with stirring. After dropping, the mixture was stirred overnight at room temperature. The solvent was evaporated from the reaction mixture in vacuo, methylene chloride was added to the residue, and insoluble matter was removed therefrom by filtration. The solvent was evaporated in vacuo from the filtrate to give 2.3 g of oily product. This was crystallized from ethyl acetate and further recrystallized to give 2.1 g of desired product, m.p. 147°-148.5° C.

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