Reaction Steps
This compound was prepared, starting from compound 5 (100 mg, 0.44 mmol) and ethyl 6-iodoimidazo[1,2-a]pyridine-2-carboxylate (75) (197 mg, 0.62 mmol) (Sunberg, R. J.; Biswas, S.; Murthi, K. K.; Rowe D.; McCall, J. W.; Dzimianski, M. T. Bis-cationic heteroaromatics as macrofilaricides: synthesis of bis-amidine and bis-guanylhydrazone derivatives of substituted imidazo[1,2-a]pyridines. J. Med. Chem. 1998, 41, 4317-4328.), according to the procedure developed for compound 10. Reaction time under reflux: 12 h; the purification was performed using column chromatography (Al2O3, CH2Cl2/EtOH, 98/2, v/v) to give compound 76 (180 mg, 0.36 mmol) as a yellow oil. Yield 58%; Rf (Al2O3, CH2Cl2/EtOH, 98/2, v/v) 0.61; IR (CCl4) ν 1249, 1283, 1466, 1564, 1669, 2800-3000, 3411 cm−1; 1H NMR (200 MHz, CDCl3) δ 1.08 (t, 3H, J=7.1 Hz), 2.71 (q, 2H, J=7.1 Hz), 2.81 (t, 2H, J=6.0 Hz), 2.97 (t, 2H, J=5.9 Hz), 3.55 (q, 2H, J=6.0 Hz), 4.11 (t, 2H, J=5.9 Hz), 6.98 (dd, 1H, J=4.8, 7.8 Hz), 7.23 (d, 1H, J=9.6 Hz), 7.31 (m, 1H), 7.34 (dd, 1H, J=1.6, 9.6 Hz), 7.64 (td, 1H, 4JH-F=1.5 Hz, J=1.5, 4.8 Hz), 7.77 (m, 1H), 8.09 (s, 1H), 8.43 (se, 1H); ESI-MS m/z 497.9 [M+H]+.
