## 3 Experimental Section
### Synthesis of 1-(2-[N-(4-methoxybenzylidene)-hydrazino]-4-methylthiazol-5-yl]-ethanone
**Synthesis of thiazole derivatives 10a-e and 13a-e:**  
A catalytic amount of TEA (0.07 mL, 1 mmol) was added to a mixture of the appropriate hydrazonoyl chlorides **8a-e** or **11a-e** (1 mmol) and compound **7** (0.362 g, 1 mmol) in dioxane (20 mL). The formed mixture was refluxed for 2-5 h (followed by TLC). The formed product was isolated by filtration and recrystallized from ethanol to give pure **10a-e** and **13a-e**. The analytical data of the products **10a-e** and **13a-e** are depicted as shown below:  
**Compound 10a:**  
Orange solid, 71% yield; m.p. 181-183 \({}^{\circ}\)C; \(\delta_{\rm H}\) (DMSO-\(d_{6}\)): 1.89, 2.36, 2.49 (3s, 9H, 3 CH\({}_{3}\)), 3.82 (s, 3H, OCH\({}_{3}\)), 6.97-7.68 (m, 9H, Ar-H), 8.05 (s, 1H, N=CH), 10.55, 11.05 (2 brs, 3H, 2 NH) ppm; \(\delta_{\rm C}\) (DMSO-\(d_{6}\)): 9.0, 14.4, 26.8 (CH\({}_{3}\)), 58.3 (OCH\({}_{3}\)), 112.1, 114.5, 116.0, 122.8, 127.5, 130.0, 130.6, 131.4, 133.7, 138.2, 145.2, 147.3, 154.2, 159.5, 162.1, 165.7 (Ar-C or C=N) ppm; IR (KBr): \(v\) 3433, 3240 (2 NH), 3046, 2924 (C-H) cm\({}^{-1}\); MS _m/z_ (%): 504 (M\({}^{+}\)), 412, 335, 250 (100), 173, 141, 91, 77, 63, 55. Anal. Calcd for C\({}_{24}\)H\({}_{24}\)N\({}_{8}\)OS\({}_{2}\) (504.63): C, 57.12; H, 4.79; N, 22.21. Found: C, 57.01; H, 4.58; N, 22.05%. **Compound 10b:**  
Orange solid, 73% yield; m.p. 211-213 \({}^{\circ}\)C; \(\delta_{\rm H}\) (DMSO-\(d_{6}\)): 1.89, 2.25, 2.54, 2.57 (4s, 12H, 4 CH\({}_{3}\)), 3.80 (s, 3H, OCH\({}_{3}\)), 7.03-7.73 (m, 8H, Ar-H), 8.19 (s, 1H, N=CH), 10.63, 10.97 (2 brs, 2H, 2 NH) ppm; \(``\)a \({}^{13}\)C NMR spectrum could not be obtained due to insolubility; IR (KBr): \(v\) 3433, 3218 (2 NH), 3037, 2931 (C-H), 1605, 1504, 1242, 1165, 1026 (C-H), 1496, 1242, 1172, 1026 cm\({}^{-1}\); MS _m/z_ (%): 518 (M\({}^{+}\)), 490, 343, 287, 204, 134, 106, 91 (100), 77, 65, 55. Anal. Calcd for C\({}_{25}\)H\({}_{26}\)N\({}_{8}\)OS\({}_{2}\) (518.66): C, 57.89; H, 5.05; N, 21.60. Found: C, 57.98; H, 5.18; N, 21.48%. **Compound 10c:**  
Red solid, 72% yield; m.p. 198-200 \({}^{\circ}\)C; \(\delta_{\rm H}\) (DMSO-\(d_{6}\)): 1.89, 2.48, 2.55 (3s, 9H, 3 CH\({}_{3}\)), 3.81 (s, 3H, OCH\({}_{3}\)), 7.0-8.09 (m, 8H, Ar-H), 8.17 (s, 1H, N=CH), 10.63, 10.96 (2 brs, 2H, 2 NH) ppm; \(\delta_{\rm C}\) (DMSO-\(d_{6}\)): 9.0, 14.4, 26.4 (CH\({}_{3}\)), 58.4 (OCH\({}_{3}\)), 116.9, 117.0, 121.3, 122.6, 126.4, 126.5, 126.7, 133.9, 134.2, 137.3, 137.4, 138.5, 138.7, 145.2, 158.8, 161.2 (Ar-C or C=N) ppm; IR (KBr): \(v\) 3433, 3217 (2 NH), 3070, 2924 (C-H), 1604, 1496, 1242, 1165, 1095 cm\({}^{-1}\); MS _m/z_ (%): 539 (M\({}^{+}\)), 363, 287, 153, 127, 111 (100), 91, 71, 55. Anal. Calcd for C\({}_{24}\)H\({}_{23}\)CN\({}_{8}\)OS\({}_{2}\) (539.08): C, 53.47; H, 4.30; N, 20.79. Found: C, 53.29; H, 4.17; N, 20.55%. **Compound 10d:**  
Brown solid, 77% yield; m.p. 236-238 \({}^{\circ}\)C; \(\delta_{\rm H}\) (DMSO-\(d_{6}\)): 1.88, 2.49, 2.61 (3s, 9H, 3 CH\({}_{3}\)), 3.82 (s, 3H, OCH\({}_{3}\)), 6.99-8.16 (m, 8H, Ar-H), 8.18 (s, 1H, N=CH), 10.99, 11.02 (2 brs, 2H, 2 NH) ppm; \(``\)a \({}^{13}\)C NMR spectrum could not be obtained due to insolubility; IR (KBr): \(v\) 3433, 3224 (2 NH), 3029, 2939 (C-H), 1609 (C=N), 1496, 1319, 1249, 1103, 1026 cm\({}^{-1}\); MS _m/z_ (%): 549 (M\({}^{+}\)), 519, 374, 288, 207, 133, 108, 65 (100), 55. Anal. Calcd for C\({}_{24}\)H\({}_{23}\)N\({}_{8}\)OS\({}_{2}\) (549.63): C, 52.45; H, 4.22; N, 22.94. Found: C, 52.61; H, 4.06; N, 22.72%. **Compound 10e:**  
Dark red solid, 73% yield; m.p. 209-211 \({}^{\circ}\)C; \(\delta_{\rm H}\) (DMSO-\(d_{6}\)): 1.91, 2.51, 2.63 (3s, 9H, 3 CH\({}_{3}\)), 3.83 (s, 3H, OCH\({}_{3}\)), 7.00-7.71 (m, 7H, Ar-H), 8.07 (s, 1H, N=CH), 9.64, 11.90 (2 brs, 2H, 2 NH) ppm; \(``\)a \({}^{13(%): 573 (M\({}^{+}\)), 397, 287, 161 (100), 153, 134, 112, 90, 77, 63. Anal. Calcf for C\({}_{24}\)H\({}_{22}\)Cl\({}_{2}\)N\({}_{8}\)OS\({}_{2}\) (573.52): C, 50.26; H, 3.87; N, 19.54. Found: C, 50.14; H, 3.80; N, 19.33%. **Compound 13a:**  
Yellow solid, 68% yield; m.p.