Dichloromethane → Trifluoroacetic acid

Participants

Reaction Steps

tert-Butyl(R)-1-(biphenyl-3-yl)-4-((R)-3-(1-(3-methoxypropyl)-1H-benzo[d]imidazol-2-yl)piperidin-1-yl)-4-oxobutan-2-ylcarbamate (52A) (0.05 mmol, 0.030 g) was weighed into a 20 mL round-bottomed flask equipped for stirring under nitrogen. CH2Cl2 (1 mL) and trifluoroacetic acid (1 mL) were 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 (R)-3-amino-4-(biphenyl-3-yl)-1-((R)-3-(1-(3-methoxypropyl)-1H-benzo[d]imidazol-2-yl)piperidin-1-yl)butan-1-one (122) as its trifluoroacetic acid salt and as a white flocculent solid (0.021 mmol, 0.013 g, 42% yield). 1H NMR (400 MHz, DMSO-d5) δ ppm 1.39-1.58 (m, 1H) 1.73-2.15 (m, 5H) 2.60-2.88 (m, 4H) 2.90-3.13 (m, 4H) 3.15-3.25 (m, 3H) 3.30-3.51 (m, 3H) 4.07-4.32 (m, 2H) 4.34-4.68 (m, 3H) 7.23-7.32 (m, 1H) 7.33-7.52 (m, 6H) 7.54-7.61 (m, 2H) 7.62-7.80 (m, 4H). ESI-MS: m/z 511.2 (M+H)+.

Provenance & Evidence