Trifluoroacetic acid → 4-{[4-(4-pyridin-2-yl-1H-imidazol-1-yl)piperidin-1-yl]methyl}phenyl-1,6-naphthyridin-5(6H)-one trifluoroacetic acid salt

Participants

Reaction Steps

To a solution of tert-butyl 4-(4-pyridin-2-yl-1H-imidazol-1-yl)piperidine-1-carboxylate (300 mg, 0.9 mmol) in CH2Cl2 (4 mL) was added trifluoroacetic acid (2 mL). The resulting solution was stirred at room temperature for 1 h. The solvents were removed in vacuo and the residue was dried under vacuum for a further 2 h. The residue was dissolved in a solution of triethylamine (1 mL) in CH2Cl2 (3 mL). The reaction mixture was stirred for 1 h at room temperature and sodium triacetoxyborohydride (381 mg, 1.8 mmol), 4-(5-oxo-3-phenyl-5,6-dihydro-1,6-naphthyridin-2-yl)benzaldehyde (295 mg, 0.9 mmol) and molecular sieves were added. Stirring was continued at room temperature for 16 h and the reaction quenched by addition of methanol. The residue was purified by HPLC (phenomenex column, 35%-100% acetonitrile/water+0.1% TFA) to afford 3-phenyl-2-(4-{[4-(4-pyridin-2-yl-1H-imidazol-1-yl)piperidin-1-yl]methyl}phenyl-1,6-naphthyridin-5(6H)-one trifluoroacetic acid salt as a yellow oil. 1H NMR (500 MHz, CD3OD) δ 8.56 (m, 3H), 8.28 (s, 1H), 8.10 (m, 1H), 7.99 (m, 1H), 7.45 (m, 1H), 7.42 (m, 5H), 7.21 (m, 3H), 7.15 (m, 2H), 6.77 (m, 1H), 4.62 (m, 1H), 4.34 (s, 2H), 3.55 (m, 2H), 3.21 (m, 2H), 2.39 (m, 4H).

Provenance & Evidence