Trifluoroacetic acid → Trifluoroacetic acid

Participants

Reaction Steps

tert-Butyl (R)-4-((R)-3-(1-(3-methoxypropyl)-1H-benzo[d]imidazol-2-yl)piperidin-1-yl)-1-(naphthalen-2-yl)-4-oxobutan-2-ylcarbamate (7E) (0.257 mmol, 0.150 g) was added to a 10 mL round-bottomed flask equipped for stirring under nitrogen and dissolved in CH2Cl2 (2 mL). Trifluoroacetic acid (2 mL) was then added and the solution was stirred at room temperature for 2 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 CH3CN in H2O (25-95%). 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((R)-3-(1-(3-methoxypropyl)-1H-benzo[d]imidazol-2-yl)piperidin-1-yl)-4-(naphthalen-2-yl)butan-1-one (74) as its trifluoroacetic acid salt and as a white flocculent solid (0.152 mmol, 0.091 g, yield 59%) 1H NMR (400 MHz, DMSO-d6) δ ppm 1.42-1.56 (m, 1H) 1.75-2.00 (m, 3H) 2.03-2.18 (m, 2H) 2.62-2.75 (m, 3H) 2.90-3.00 (m, 1H) 3.03-3.29 (m, 8H) 3.34-3.45 (m, 2H) 3.77-3.87 (m, 2H) 4.09-4.68 (m, 3H) 7.42-7.55 (m, 5H) 7.72-8.02 (m, 6H) ESI-MS: 485.5 m/z (M+H)+.

Provenance & Evidence