Diethyl Ether → 3-(5-(1-(4-cyanophenyl)-1H-pyrazol-5-yl)-6-methyl-2-oxo-1-(3-(trifluoromethyl)phenyl)-1,2-dihydropyridine-3-carboxamido)-N,N,N-trimethylpropan-1-aminium benzene sulfonate

Participants

Reaction Conditions

Reaction Steps

A column of DOWEX 1×8 (50-100 mesh, Cl−) (approximately 10 g) was activated by passing through a aqueous saturated NaHCO3-solution (approximately 70 mL), followed by washing with H2O (100 mL) (until the pH of the eluent was neutral) and MeOH (40 mL). 3-(5-(1-(4-cyanophenyl)-1H-pyrazol-5-yl)-6-methyl-2-oxo-1-(3-(trifluoromethyl)phenyl)-1,2-dihydropyridine-3-carboxamido)-N,N,N-trimethylpropan-1-aminium acetate (300 mg, 0.48 mmol, Example 8) was dissolved in MeOH (2 mL) and the solution was allowed to pass slowly through the column followed by about 20 mL of MeOH. Benzenesulfonic acid (76 mg, 0.48 mmol) was added to the filtrate and the solution was evaporated, the residue was co-evaporated with EtOH and then dissolved in EtOH (0.5 mL) and THF (3.5 mL). The mixture was heated at 50° C. for 0.5 hr and was then stirred at room temperature over the weekend. No precipitate had formed over this time. Diethylether (3 mL) was added and the mixture was stirred at room temperature. After 1 hr a solid had started to precipitate and the slurry was stirred overnight. The precipitate was filtered off, washed with heptane and dried to afford the title compound as an off-white solid (300 mg, 86%); 1H NMR (400 MHz, dmso) δ 1.81 (3H, s), 1.90 (2H, m), 3.01 (9H, s), 3.27 (4H, m), 6.72 (1H, d), 7.30 (3H, m), 7.59 (2H, m), 7.67 (2H, d), 7.71 (1H, d), 7.85 (2H, m), 7.94 (4H, m), 8.04 (1H, s), 9.41 (1H, t). APCI-MSm/z: 563 [M+]

Provenance & Evidence