Triphenylphosphine → Tert-butyl 4-(7-(1-(4-(trifluoromethyl)phenyl)piperidin-4-yloxy)imidazo[1,2-a]pyridine-2-carboxamido)piperidine-1-carboxylate

Participants

Reaction Steps

To a stirred solution of tert-butyl 4-(7-hydroxyimidazo[1,2-a]pyridine-2-carboxamido)piperidine-1-carboxylate (0.18 g, 0.50 mmol) in toluene (4 mL) at room temperature was added diisopropyl azodicarboxylate (0.12 g, 0.6 mmol), 1-(4-(trifluoromethyl)phenyl)-piperidin-4-ol (0.12 g, 0.5 mmol), and triphenylphosphine (0.16 g, 0.6 mmol). The mixture was stirred at room temperature overnight and then concentrated under reduced pressure. The residue obtained was purified by flash chromatography (silica gel, methylene chloride/methanol/30% ammonium hydroxide=20/1/0.01) to afford tert-butyl 4-(7-(1-(4-(trifluoromethyl)phenyl)piperidin-4-yloxy)imidazo[1,2-a]pyridine-2-carboxamido)piperidine-1-carboxylate as a off-white solid (0.13 g, 44%). 1H-NMR (CDCl3, 300 MHz): δ 7.97 (m, 2H), 7.47 (m, 2H), 7.18 (m, 1H), 6.95 (m, 2H), 6.81 (s, 1H), 6.58 (m, 1H), 4.56 (m, 1H), 4.11 (m, 3H), 3.61 (m, 2H), 3.26 (m, 2H), 2.92 (m, 2H), 2.15 (m, 2H), 2.03 (m, 4H), 1.66 (m, 2H), 1.47 (s, 9H) ppm; MS (ESI): 588.4 (M+1).

Provenance & Evidence