tert-Butyl acrylate → (E)-tert-Butyl 6-(3-tert-butoxy-3-oxoprop-1-enyl)-2-oxo-2,4-dihydro-1H-spiro[[1,8]naphthyridine-3,4'-piperidine]-1'-carboxylate

Participants

Reaction Steps

Tert-Butyl acrylate (3.9 mL, 26.8 mmol), diisopropylethylamine (2.46 mL, 14.1 mmol) and P(o-tolyl)3 (409 mg, 1.34 mmol) were successively added to a suspension of tert-butyl 6-bromo-2-oxo-2,4-dihydro-1H-spiro[[1,8]naphthyridine-3,4′-piperidine]-1′-carboxylate (2.66 g, 6.7 mmol) in propionitrile (107 mL) and dimethylformamide (40 mL) in a sealed tube. The resulting mixture was then purged with argon prior to the addition of palladium acetate (151 mg, 0.673 mmol). The mixture was purged with argon again and refluxed overnight. The reaction mixture was then filtered on Celite® and the cake was washed with DCM (50 mL). The filtrate was concentrated to dryness and the residue was triturated with dichloromethane. The title product was obtained as a light grey solid (1.83 g, 61%, py 79.9%).

Provenance & Evidence