Hydrochloric Acid → {6-Cyano-3-[2,2-difluoro-2-(5-methyl-pyridin-2-yl)-ethylamino]-2-fluoro-phenyl}-acetic acid

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Reaction Steps

{6-Cyano-3-[2,2-difluoro-2-(5-methyl-pyridin-2-yl)-ethylamino]-2-fluoro-phenyl}-acetic acid ethyl ester (968 mg, 2.57 mmol), prepared as described in the previous step, was dissolved into MeOH:THF:H2O (51 mL, 1:2:1) and treated with LiOH (92 mg, 3.85 mmol, 1.5×). After 1.5 h, the reaction was neutralized with 428 μL, 12N HCl and concentrated in vacuo. The crude material was diluted with toluene and concentrated (3×25 mL) to afford the saponification product {6-cyano-3-[2,2-difluoro-2-(5-methyl-pyridin-2-yl)-ethylamino]-2-fluoro-phenyl}-acetic acid. {6-cyano-3-[2,2-difluoro-2-(5-methyl-pyridin-2-yl)-ethylamino]-2-fluoro-phenyl}-acetic acid, HCl salt of [N,N′-di(tert-butoxycarbonyl)]-2-aminoethoxyguanidine (1.8 g, 5.13 mmol, 2×) (prepared as described in Example 1d), and BOP (1.8 g, 4.16 mmol, 1.6×) were dissolved into CH3CN/CH2Cl2 (12 mL, 1:1) and cooled to 0° C. DIEA (2.7 mL, 15.6 mmol, 6×) was added dropwise and the reaction continued for 12 h, allowing the ice bath to warm to rt. The reaction was partitioned between EtOAc (50 mL) and H2O (50 mL), the organic phase dried over Na2SO4, and concentrated to afford the crude product as a white amorphous solid. Purification via flash chromatography (20% EtOAc/CH2Cl2) afforded the product as a white solid (832 mg, 1.28 mmol, 50% yield). 1H NMR (300 Hz, CDCl3) δ 9.14 (s, 1H), 8.49 (s, 1H), 7.61, m, 2H), 6.75 (t, J=8.2 Hz, 1H), 4.13 (m, 4H), 3.83 (s, 2H), 3.61 (m, 2H), 2.41 (s, 3H), 1.51 (s, 9H), 1.47 (s, 9H); LC/MS (m/z) [M+1]+ 650.3 (calculated for C30H39F3N7O6, 650.7).

Provenance & Evidence