Triethylamine → Tert-butyl 3-((2-bromo-5-nitropyridin-4-yl)amino)piperidine-1-carboxylate

Participants

Reaction Steps

The tert-butyl 3-aminopiperidine-1-carboxylate (1.43 g, 7.14 mmol, 1.0 eq) was added dropwise to a solution of 2,4-dibromo-5-nitropyridine (2 g, 7.14 mmol, 1.0 eq) and Et3N (0.73 g, 7.14 mmol, 1.0 eq) in EtOH (20 mL) at reflux temperature. The reaction mixture was heated at refluxing for 16 h and then the solvent was concentrated in vacuo to afford a residue. The residue was treated with 1 N NaOH solution and extraction with EtOAc. The organic phase was separated, dried (Na2SO4) and concentration in vacuo to afford an residue which was purified by silica gel column chromatography with EtOAc in PE (⅕ v/v) to give the title compound (1.24 g, 42%) as yellow solid. 1H NMR (400 MHz, CDCl3) δ: 8.99 (s, 1H), 8.25 (s, 1H), 6.98 (s, 1H), 3.81-3.79 (m, 1H), 3.61-3.60 (m, 2H), 3.37-3.35 (m, 2H), 2.02 (m, 1H), 1.86-1.77 (m, 3H), 1.47 (s, 9H). ESI-MS (M+H+): 401.0.

Provenance & Evidence