To a solution of 1.81 g (7.5 mmol) of 5-(4-chlorobutylthio)imidazo[1,2-a]pyridine and 1.59 g (7.5 mmol) of 5-(2-thienylmethylene)thiazolidine-2,4-dione in 70 ml of N,N-dimethylformamide, 1.12 ml (7.5 mmol) of 1,8-diazabicyclo[5.4.0-7-undecene was added, followed by heating at 80° C. for 16 hours. After cooling, the reaction mixture was poured into water, extracted with ethyl acetate, washed with water and dried, after which the solvent was distilled off. The residue was purified by column chromatography (eluent, hexane/ethyl acetate=2/1→1/1→ethyl acetate). The resulting crude crystal was purified by recrystallization (solvent, chloroform/diethyl ether) to yield 1.54 g (49.5%, light yellow crystal) of the desired product.m.p. 116.0°-117.0° C.; 1H-NMR (CDCl3, 200 MHz) δ 1.64-1.92 (4H, m), 3.03 (2H, t, J=7.0 Hz), 3.76 (2H, t, J=7.0 Hz), 6.92 (1H, dd, J=1.0, 7.0 Hz), 7.15 (1H, dd, J=7.2, 9.2 Hz), 7.21 (1H, dd, J=3.8, 5.2 Hz), 7.42 (1H, d, J=3.6 Hz), 7.58 (1H, d, J=9.0 Hz), 7.68 (1H, d, J=5.0 Hz), 7.70 (1H, d, J=1.4 Hz), 7.85 (1H, s), 8.05 (1H, s); IR (KBr) 1728, 1678, 1599, 1369, 1128, 773, 727 cm-1 ; Anal. Calcd for C19H17N3O2S3 : C, 54.92; H, 4.12; N, 10.11. Found: C, 54.67, H, 4.18; N, 10.03
