Dimethylformamide → tert-butyl 4-(7-chloro-2-oxo-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazin-1-yl)piperidine-1-carboxylate

Participants

Reaction Steps

To an N,N-dimethylformamide suspension (60 ml) of tert-butyl 4-[(5-chloro-2-hydroxypiperidin-3-yl)amino]piperidine-1-carboxylate (3.00 g) and potassium carbonate (3.79 g) was added chloroacetyl chloride (1.09 ml), followed by stirring at room temperature for 30 minutes, and at 140° C. for 4 hours. After the reaction solution was brought back to room temperature, water and ethyl acetate were added, and the solution was separated. The organic layer was washed with water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to afford tert-butyl 4-(7-chloro-2-oxo-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazin-1-yl)piperidine-1-carboxylate (1.33 g).

Provenance & Evidence