Ammonium Chloride → Tert-butyl 3-((5-amino-2-bromopyridin-4-yl)amino)piperidine-1-carboxylate

Participants

Reaction Steps

To a mixture of tert-butyl 3-((2-bromo-5-nitropyridin-4-yl)amino)piperidine-1-carboxylate. (1.24 g, 3.01 mmol, 1.0 eq) and NH4Cl (2.43 g, 45 mmol, 15 eq) was added a 2:1 mixture EtOH/water (30 mL). The reaction mixture was heated to reflux, then iron powder (0.67 g, 12 mmol, 3.5 eq) was added in portions over 15 min and the suspension was continued to be heated at refluxed for 16 h. The reaction mixture was cooled to rt, diluted with CH2Cl2 (300 mL) and filtered through celite. The organic layer was washed with water (50 mL×2) and brine (50 mL), dried (Na2SO4), filtered and concentrated in vacuo to give the title compound (1.2 g, 100%) which was used to next step without further purification. 1H NMR (400 MHz, CDCl3) δ: 7.66 (s, 1H), 6.63 (s, 1H), 4.51-4.39 (m, 1H), 3.89-3.86 (m, 1H), 3.67-3.63 (m, 1H), 3.41-3.10 (m, 4H), 2.09-1.95 (m, 1H), 1.74-1.60 (m, 3H), 1.47 (s, 9H). ESI-MS (M+H+): 371.0.

Provenance & Evidence