Trifluoroacetic acid → (+/-)-5-[3-Methyl-1-(4'-trifluoromethyl-biphenyl-4-yl)-butylamino]-pyrimidine-2-carboxylic acid methyl ester

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(+/−)-5-{tert-Butoxycarbonyl-[3-methyl-1-(4′-trifluoromethyl-biphenyl-4-yl)-butyl]-amino}-pyrimidine-2-carboxylic acid methyl ester (1.498 g impure) was dissolved in dichloromethane (10 mL) and trifluoroacetic acid (3 mL) was added. This was stirred at room temperature. At 70 min, another 3 mL of trifluoroacetic acid was added. At 90 min, the reaction was concentrated and the material was partitioned between ethyl acetate and sat. NaHCO3. The aqueous layer was extracted with ethyl acetate and the combined organics dried over MgSO4. Purification by silica gel flash chromatography (ethyl acetate/heptane) gave (+/−)-5-[3-methyl-1-(4′-trifluoromethyl-biphenyl-4-yl)-butylamino]-pyrimidine-2-carboxylic acid methyl ester (0.620 g) as a white foam. 1H NMR (400 MHz, CDCl3, δ): 8.16 (s, 2 H) 7.67-7.73 (m, 2 H) 7.61-7.66 (m, 2 H) 7.56 (d, J=8.2 Hz, 2 H) 7.39 (d, J=8.2 Hz, 2 H) 4.68 (d, J=5.7 Hz, 1 H) 4.46-4.57 (m, 1 H) 3.98 (s, 3 H) 1.79-1.92 (m, 1 H) 1.64-1.79 (m, 2 H) 1.05 (d, J=6.2 Hz, 3 H) 0.99 (d, J=6.2 Hz, 3 H); MS (M+1): 444.3.

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