Trifluoroacetic acid → Trifluoroacetic acid

Participants

Reaction Steps

Methyl 4′-((R)-2-(tert-butoxycarbonylamino)-4-((R)-3-(1-(3-methoxypropyl)-1H-benzo[d]imidazol-2-yl)piperidin-1-yl)-4-oxobutyl)biphenyl-4-carboxylate (53A) (0.08 mmol, 0.054 g) was weighed into a 20 mL scintillation vial and dissolved in CH2Cl2 (2 mL). Trifluoroacetic acid (2 mL) was then added and the solution was stirred at room temperature for 2 hrs. 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 (20-55% 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 methyl 4′-((R)-2-amino-4-((R)-3-(1-(3-methoxypropyl)-1H-benzo[d]imidazol-2-yl)piperidin-1-yl)-4-oxobutyl)biphenyl-4-carboxylate (123) as its trifluoroacetic acid salt and as a white flocculent solid. (0.07 mmol, 0.040 g, 88% yield). 1H NMR (400 MHz, DMSO-d6) δ ppm 1.40-1.63 (m, 1H) 1.73-2.21 (m, 5H) 2.56-2.87 (m, 3H) 2.91-3.15 (m, 3H) 3.16-3.52 (m, 5H) 3.68-3.92 (m, 4H) 4.05-4.70 (m, 5H) 7.37-7.53 (m, 4H) 7.68-7.87 (m, 6H) 8.02-8.07 (m, 2H). ESI-MS: 569.3 m/z (M+H)+.

Provenance & Evidence