Methanol → 5,5,5-Trifluoro-2-methoxy-carbonylamino-pentanoic acid

To a solution of 5,5,5-Trifluoro-2-methoxycarbonylamino-pentanoic acid methyl ester (194 mg, 0.80 mmol) in methanol (3 mL) was added an aqueous LiOH solution (1M, 2 mL, 2 mmol). The resulting solution was stirred at room temperature for 45 minutes and then washed with ethyl acetate. The ethyl acetate washing was discarded and the aqueous layer was acidified with concentrated HCl. The acidified aqueous layer was extracted twice with ethyl acetate. The combined organics were washed with brine, dried (MgSO4), and concentrated to give clean 5,5,5-Trifluoro-2-methoxy-carbonylamino-pentanoic acid. To a solution of the pentanoic acid in dimethylformamide (2 mL) was added HATU (300 mg, 0.79 mmol). After stirring for 5 minutes, a solution of 2-{5-[4′-(2-pyrrolidin-2-yl-3H-imidazol-4-yl)-biphenyl-4-yl]-1H-imidazol-2-yl}-pyrrolidine-1-carboxylic acid tert-butyl ester (412 mg, 0.79 mmol) in dimethylformamide (1.9 mL) was added to the reaction, followed immediately by diisopropylethylamine (275 μL, 1.58 mmol). The reaction was stirred for 1 hour at room temperature then diluted with ethyl acetate. The organic layer was washed with water and brine, dried (MgSO4), concentrated and purified by flash chromatography to yield 2-[5-(4′-{2-[1-(5,5,5-trifluoro-2-methoxycarbonylamino-pentanoyl)-pyrrolidin-2-yl]-3H-imidazol-4-yl}-biphenyl-4-yl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester (340 mg, 59%).

1. washwashed with ethyl acetate
2. extractionThe acidified aqueous layer was extracted twice with ethyl acetate
3. washThe combined organics were washed with brine
4. dry with materialdried (MgSO4)
5. concentrationconcentrated

ORD record

ord-93b530e3c2104acfb68caa9f5a2b39c0

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08841278B2