Hydrochloric Acid → 1-tert-butyl 4-ethyl 4-(3-(2-oxoquinoxalin-1(2H)-yl)propyl)piperidine-1,4-dicarboxylate

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Reaction Conditions

Reaction Steps

To 5 mL of an N,N-dimethylformamide suspension containing 0.25 g of quinoxalin-2(1H)-one, 0.10 g of 60% sodium hydride was added at room temperature, and the mixture was stirred at 50° C. for 30 minutes. Thereto was dividedly added 0.68 g of 1-tert-butyl 4-ethyl 4-(3-((methanesulfonyl)oxy)propyl)piperidine-1,4-dicarboxylate at the same temperature, and the mixture was stirred at 80 to 90° C. for 2 hours. The reaction mixture was cooled to room temperature, ethyl acetate and water were added thereto, and the resultant solution was adjusted to pH 2.0 with 6 mol/L hydrochloric acid. The organic layer was separated, and the aqueous layer was extracted with ethyl acetate. The organic layer and the extract were combined, the resultant solution was washed sequentially with water and an aqueous saturated sodium chloride solution and dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. The residue thus obtained was purified by silica gel column chromatography [eluent; hexane:ethyl acetate=1:1] to obtain 0.18 g of a yellow brown oily substance, 1-tert-butyl 4-ethyl 4-(3-(2-oxoquinoxalin-1(2H)-yl)propyl)piperidine-1,4-dicarboxylate.

Provenance & Evidence