1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → (E)-6-(3-(3-acetylazetidin-1-yl)-3-oxoprop-1-enyl)-1'-methyl-1H-spiro[[1,8]naphthyridine-3,4'-piperidin]-2(4H)-one

Participants

Reaction Steps

1-(Azetidin-3-yl)ethanone hydrochloride (110 mg, 0.8 mmol), EDCI (153 mg, 0.8 mmol), HOBt (108 mg, 0.8 mmol) and diisopropylethylamine (700 μL, 4.0 mmol) were successively added to a solution of (E)-3-(1′-methyl-2-oxo-2,4-dihydro-1H-spiro[[1,8]naphthyridine-3,4′-piperidine]-6-yl)acrylic acid hydrochloride (136 mg, 0.4 mmol) in dimethylformamide (15 mL) at room temperature. The reaction mixture was stirred overnight. After concentration to dryness, the residue was purified by chromatography on silica gel using dichloromethane/methanol/ammoniac (9:1:0.1) as eluent. Precipitation in a mixture DCM/pentane allowed isolation of the title product as a yellow solid (44.6 mg, 29%).

Provenance & Evidence