ethyl 1-(4-chlorophenyl)-2-oxopyrrolidine-3-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Under ice-cooling, 3.9 g of sodium borohydride was added portionwise to a solution of 30.0 g of 1-(4-chlorophenyl)-3-ethoxycarbonyl-2-pyrrolidinone and 15 g of anhydrous calcium chloride in 150 mL of methanol. After completion of the reaction, the mixture was concentrated, and water and ethyl acetate were added. The mixture was acidified with diluted hydrochloric acid. After separation, the organic layer was washed with water, dried over anhydrous magnesium sulfate and concentrated. The residue was crystallized with n-hexane-ethyl ether. The crystals were collected by filtration, washed with a mixture of n-hexane and diethyl ether and dried in vacuo to give 23.3 g of the title compound. Under ice-cooling After completion of the reaction the mixture was concentrated water and ethyl acetate were added After separation the organic layer was washed with water dried over anhydrous magnesium sulfate concentrated The residue was crystallized with n-hexane-ethyl ether The crystals were collected by filtration washed with a mixture of n-hexane and diethyl ether dried in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a suspension of 25 g of sodium hydride (60% oil dispersion) in 100 mL of tetrahydrofuran was added 37 g of diethyl carbonate. Under reflux, to the mixture was added dropwise a solution of 52.0 g of 1-(4-chlorophenyl)-2-pyrrolidinone in 150 mL of tetrahydrofuran over about 1.5 hours. After refluxing for 4.5 hours, the reaction mixture was cooled, and carefully poured into ice-water. The mixture was made to weakly alkaline with diluted hydrochloric acid and extracted with 300 mL of ethyl acetate. The organic layer was washed sequentially with water, aqueous sodium bicarbonate solution and water, dried over anhydrous magnesium sulfate and concentrated to give an oil. To the residue was added 200 mL of n-hexane, and the precipitated crystals were collected by filtration. The crystals were washed with n-hexane and dried in vacuo to give 60 g of the title compound. Under reflux, to the mixture After refluxing for 4.5 hours the reaction mixture was cooled extracted with 300 mL of ethyl acetate The organic layer was washed sequentially with water, aqueous sodium bicarbonate solution and water dried over anhydrous magnesium sulfate concentrated to give an oil the precipitated crystals were collected by filtration The crystals were washed with n-hexane dried in vacuo