## 3 Experimental Section
### Synthesis of 1-(2-[N-(4-methoxybenzylidene)-hydrazino]-4-methylthiazol-5-yl]-ethanone
205-207 \({}^{\circ}\)C; \(\delta_{\rm H}\) (DMSO-\(d_{6}\)): 2.34, 2.45 (2s, 6H, 2 CH\({}_{3}\)), 3.82 (s, 3H, OCH\({}_{3}\)), 7.03-7.99 (m, 9H, Ar-H), 8.07 (s, 1H, N=CH), 9.65, 10.55, 12.11(3 brs, 3H, 3 NH) ppm; 8\({}_{\rm C}\) (DMSO-\(d_{6}\)): 9.0, 14.5 (CH\({}_{3}\)), 58.1 (OCH\({}_{3}\)), 115.0, 117.5, 119.8, 123.1, 126.7, 129.8, 130.2, 131.9, 135.7, 137.2, 143.1, 149.1, 152.1, 156.6, 163.0 (Ar-C or C=N), 174.0 (C=O) ppm; IR (KBr): \(v\) 3419, 3326, 3155 (3 NH), 3039, 2908 (C-H), 1712 (C=O), 1611 (C=N), 1558, 1435, 1303, 1249, 1095 cm\({}^{-1}\); MS \(m/z\) (%): 506 (M\({}^{+}\)), 383, 241, 169 (100), 106, 91, 77, 54. Anal. Calcd for C\({}_{23}\)H\({}_{22}\)N\({}_{8}\)O\({}_{2}\)S\({}_{2}\) (506.60): C, 54.53; H, 4.38; N, 22.12. Found: C, 54.53; H, 4.38; N, 22.12%. **Compound 13b:**  
Yellow solid, 67% yield; m.p. 215-217 \({}^{\circ}\)C; \(\delta_{\rm H}\) (DMSO-\(d_{6}\)): 2.16, 2.38, 2.51 (3s, 9H, 3 CH\({}_{3}\)), 3.81 (s, 3H, OCH\({}_{3}\)), 7.0-7.85 (m, 8H, Ar-H), 8.05 (s, 1H, N=CH), 10.04, 10.40, 10.48 (3 brs, 3H, 3 NH) ppm; \"a \({}^{13}\)C NMR spectrum could not be obtained due to insolubility; IR (KBr): \(v\) 3422, 3316, 3203 (3 NH), 3044, 2927 (C-H), 1709 (C=O), 1606 (C=N), 1470, 1249, 1138, 1036 cm\({}^{-1}\); MS \(m/z\) (%): 520 (M\({}^{+}\)), 466, 307, 216, 119, 91 (100), 77, 57. Anal. Calcd for C\({}_{24}\)H\({}_{24}\)N\({}_{8}\)O\({}_{2}\)S\({}_{2}\) (520.63): C, 55.37; H, 4.65; N, 21.52. Found: C, 55.16; H, 4.44; N, 21.37%. **Compound 13c:**  
Yellow solid, 68% yield; m.p. 155-157 \({}^{\circ}\)C; \(\delta_{\rm H}\) (DMSO-\(d_{6}\)): 2.35, 2.48 (2s, 6H, 2 CH\({}_{3}\)), 3.81 (s, 3H, OCH\({}_{3}\)), 7.0-7.65 (m, 8H, Ar-H), 8.10 (s, 1H, N=CH), 10.45 10.95 12.26 (3 brs, 3H, 3 NH) ppm; IR (KBr): \(v\) 3441, 3253, 3170 (3 NH), 3041, 2939 (C-H), 1681 (C=O), 1608 (C=N), 1485, 1242, 1165, 1041 cm\({}^{-1}\); MS \(m/z\) (%): 541 (M\({}^{+}\)), 407, 281, 153, 134, 111, 71, 55 (100). Anal. Calcd for C\({}_{23}\)H\({}_{21}\)ClN\({}_{8}\)O\({}_{2}\)S\({}_{2}\) (541.05): C, 51.06; H, 3.91; N, 20.71. Found: C, 51.18; H, 3.81; N, 20.53%. **Compound 13d:**  
Yellow-brown solid, 74% yield; m.p. 225-227 \({}^{\circ}\)C; \(\delta_{\rm H}\) (DMSO-\(d_{6}\)): 2.36, 2.46 (2s, 6H, 2 CH\({}_{3}\)), 2 CH\({}_{3}\)), 3.80 (s, 3H, OCH\({}_{3}\)), 7.0-8.12 (m, 9H, Ar-H + N=CH), 11.11 (br s, 1H, NH), 11.5 (br s, 1H, NH) ppm; \"a \({}^{13}\)C NMR spectrum could not be obtained due to insolubility; IR (KBr): \(v\) 3427, 3310, 3194 (3 NH), 3078, 2931 (C-H), 1705 (C=O), 1609 (C=N), 1512, 1327, 1249, 1165, 1018 cm\({}^{-1}\); MS \(m/z\) (%): 551 (M\({}^{+}\)), 470, 398, 277, 205, 133, 90 (100), 76, 63, 55. Anal. Calcd for C\({}_{23}\)H\({}_{21}\)N\({}_{8}\)O\({}_{4}\)S\({}_{2}\) (551.60): C, 50.08; H, 3.84; N, 22.85. Found: C, 50.03; H, 3.72; N, 22.70%. **Compound 13e:**  
Yellow solid, 70% yield; m.p. 145-147 \({}^{\circ}\)C; \(\delta_{\rm H}\) (DMSO-\(d_{6}\)): 2.36, 2.46 (2s, 6H, 3.82 (s, 3H, OCH\({}_{3}\)), 7.02-8.10 (m, 8H, Ar-H + N=CH), 9.95 (br s, 1H, NH), 11.05 (br s, 1H, NH) ppm; IR (KBr): \(v\) 3433, 3313, 3217 (3 NH), 3041, 2924 (C-H), 1720 (C=O), 1612 (C=N), 1541, 1242, 1147, 1038 cm\({}^{-1}\); MS \(m/z\) (%): 575 (M\({}^{+}\)), 473, 317, 204 (100), 106, 91, 57. Anal. Calcd for C\({}_{23}\)H\({}_{20}\)Cl\({}_{2}\)N\({}_{8}\)O\({}_{2}\)S\({}_{2}\) (575.49): C, 48.00; H, 3.50; N, 19.47. Found: C, 47.92; H, 3.35; N, 19.29%. **Synthesis of thiazoles 14 and 16:**  
A mixture of hydrazinecarbothioamide **7** (0.362 g, 1 mmol) and 3-chloropentane-2,4-dione **(4)** or 2-bromo-1-phenylethanone **(15)** (1 mmol) in EtOH (20 mL) was refluxed for 3 h. The formed product was recrystallized from DMF to give the corresponding thiazole derivatives **14** or **16**. **Compound 14:**  
Yellow solid, 73% yield; m.p.