Dichloromethane → Trifluoroacetic acid

Participants

Reaction Steps

(R)-tert-Butyl 4-(3-(5-methoxy-3-(3-methoxypropyl)-3H-imidazo[4,5-b]pyridin-2-yl)piperidin-1-yl)-1-(naphthalen-2-yl)-4-oxobutan-2-ylcarbamate (33E) (0.069 mmol, 0.042 g) was added to a 10 mL round-bottomed flask equipped for stirring under nitrogen. Dichloromethane (1 mL) and trifluoroacetic acid (1 mL) were then added and the resultant solution was allowed to stir under nitrogen for 4 hr. The solvent was removed in-vacuo affording a clear colored oil. This oil was re-dissolved in methanol (3 mL), filtered, and then purified by preparative LC/MS (5-55% CH3CN in H2O). The resultant fractions were collected and the solvent was removed in-vacuo affording a clear colored oil. This oil was re-dissolved in CH3CN (1 mL) and water (2 mL). The resultant solution was frozen and lyophilized to afford (R)-3-amino-1-(3-(5-methoxy-3-(3-methoxypropyl)-3H-imidazo[4,5-b]pyridin-2-yl)piperidin-1-yl)-4-(naphthalen-2-yl)butan-1-one (100) as its trifluoroacetic acid salt and as a white flocculent solid (0.067 mmol, 0.035 g, 98% yield) 1H NMR (400 MHz, DMSO-d6) δ ppm 1.37-1.58 (m, 1 H) 1.68-2.14 (m, 5H) 2.57-2.89 (m, 2H) 2.89-3.23 (m, 8H) 3.24-3.48 (m, 2H) 3.92 (d, J=2.53 Hz, 5H) 4.02-4.35 (m, 2H) 4.36-4.62 (m, 1H) 6.63-6.76 (m, 1 FI) 7.35-7.59 (m, 3 H) 7.72-8.02 (m, 5H). ESI-MS: m/z 516.2 (M+H)+.

Provenance & Evidence