To a stirred mixture of 5-(5-benzyl-1H-1,2,4-triazol-3-yl)-3-methylthiophene-2-carboxylic acid (0.13 g, 0.43 mmol), 1-hydroxybenzotriazole (0.088 g, 0.65 mmol) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.13 g, 0.65 mmol) in anhydrous N,N-dimethylformamide (2 mL) was added N,N-diisopropylethylamine (0.23 mL, 1.30 mmol), followed by the addition of 3-(aminomethyl)pyridine (0.044 mL, 0.44 mmol). The resulting reaction mixture was stirred at ambient temperature for 18 h, and diluted with ethyl acetate (75 mL). The organic layer was washed with saturated aqueous sodium bicarbonate (3×35 mL) and water (35 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography eluted with 10% methanol in dichloromethane to afford the title compound as a colorless foam (0.11 g, 67%): mp 82° C. (dec.); 1H NMR (300 MHz, DMSO-d6) δ 8.66 (t, J=5.6 Hz, 1H), 8.55 (s, 1H), 8.46 (s, 1H), 7.73 (d, J=7.9 Hz, 1H), 7.42-7.20 (m, 8H), 4.44 (d, J=5.6 Hz, 2H), 4.10 (s, 2H), 2.43 (s, 3H); MS (ES+) m/z 390.3 (M+1).
