반응 단계
3-(2-Nitro-phenyl)-2-oxo-propionic acid (1.0 mmol, 209 mg) in 5% acetic acid (2 mL) was added in to solution of 4-(3,4-dichloro-phenyl)-thiazol-2-yl-hydrazine (1.0 mmol, 259 mg) in ethanol (4 mL). The reaction mixture was stirred at 90° C. for 1 h and cooled to 0° C.; the orange solid was precipitated out, filtered and washed by water. Recrystallization from MeOH—H2O afford the final product as a yellow powder (600 mg, 66.7%). mp ; Z/E isomer was further separated by HPLC-MS, using gradient eluting solvents: 0.05% HOAc in acetonitrile 50%: 0.05% HOAc in water 50% to 0.05% HOAc in acetonitrile 75%: 0.05% HOAc in water 25% in 20 min. 1H NMR (400 MHz) δ 12.85 (br, 1H), 12.10 (br, 1H), 8.06 (d, J=8.4 Hz, 1H), 8.03(s, 1H), 7.78 (d, J=8.4 Hz, 1H), 7.64 (d, J=6.0 Hz , 2H), 7.61(s, 1H), 7.50 (t, J=7.6 Hz, 1H), 7.06 (d, J=7.6 Hz, 1H), 4.28 (s, 2H). 13C NMR (125.78 MHz) δ 166.097, 164.759, 149.785, 134.607, 134.281, 133.663, 132.596, 132.182, 131.543, 130.680, 129.559, 128.927, 127.854, 126.318, 125.795, 125.299, 108.552, 36.896. Z-isomer: 1H NMR (400 MHz) δ 12.35 (br, 1H), 12.10 (br, 1H), 8.06 (dd, J=8.4 Hz, 1H), 8.03(s, 1H), 7.78 (d, J=8.4 Hz, 1H), 7.64 (d, J=6.0 Hz, 2H), 7.61(s, 1H), 7.50 (t, J=7.6 Hz, 1H), 7.06 (d, J=7.6 Hz, 1H), 4.12 (s, 2H).
