Sodium hydride → 1-Tert-butyl 4-ethyl 4-(3-(7-methoxy-2-oxo-1,2-dihydroquinoxalin-1-yl)propyl)piperidine-1,4-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

10 mL of an N,N-dimethylformamide solution containing 1.0 g of 7-methoxyquinoxalin-2(1H)-one was subjected to azeotropic dehydration with toluene, then 0.24 g of 60% sodium hydride was added thereto at room temperature, and the mixture was stirred at 60° C. for 30 minutes. Thereto was added 2 mL of an N,N-dimethylformamide solution containing 2.3 g of 1-tert-butyl 4-ethyl 4-(3-((methanesulfonyl)oxy)propyl)piperidine-1,4-dicarboxylate, and the mixture was stirred at the same temperature for 6 hours and then left to stand for 13 hours. Thereto was further added 0.12 g of 60% sodium hydride, and the mixture was stirred for 1 hour. The reaction mixture was cooled to room temperature, and ethyl acetate and water were added thereto. 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 2:1] to obtain 0.60 g of a yellow oily substance, 1-tert-butyl 4-ethyl 4-(3-(7-methoxy-2-oxo-1,2-dihydroquinoxalin-1-yl)propyl)piperidine-1,4-dicarboxylate.

Provenance & Evidence