Pyridine → N-[4-(3-benzyl-[1,2,4]oxadiazol-5-yl)-pyridin-2-yl]-benzamide

Beteiligte Stoffe

Reaktionsschritte

To a solution of 2-benzamidoisonicotinic acid (0.35 g, 1.44 mmol) and N,N-dimethylformamide (0.1 mL) in dichloromethane (5 mL) was added oxalyl chloride (0.15 mL, 1.73 mmol) at ambient temperature. The resulting mixture was stirred at ambient temperature for 1 hour and concentrated in vacuo to dryness. The residue was dissolved in N,N-dimethylformamide (2 mL) and added to a solution of N′-hydroxy-2-phenylacetimidamide (0.24 g, 1.59 mmol) and pyridine (0.3 mL, 3.70 mmol) in N,N-dimethylformamide (1 mL) at 0° C. The reaction mixture was stirred at ambient temperature for 3 hours, diluted with ethyl acetate (40 mL), washed with water (20 mL) and brine (20 mL). The organic solution was dried over anhydrous sodium sulphate, filtered and concentrated in vacuo. The residue was dissolved in toluene (10 mL), followed by the addition of (methoxycarbonylsulfamoyl)triethylammonium hydroxide (0.53 g, 2.16 mmol). The mixture was refluxed for 1 hour and concentrated in vacuo. The residue was purified by column chromatography to give N-[4-(3-benzyl-[1,2,4]oxadiazol-5-yl)-pyridin-2-yl]-benzamide as a colorless solid (0.06 g 12%): mp 150-151° C.; 1H NMR (300 MHz, CDCl3) δ 9.06 (s, 1H), 8.69 (s, 1H), 8.46 (d, J=4.9 Hz, 1H), 7.94-7.91 (m, 2H), 7.72-7.69 (m, 1H), 7.62-7.48 (m, 3H), 7.39-7.24 (m, 5H), 4.16 (s, 2H); MS (ES+) m/z 357.5 (M+1).

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