## 2 Experimental
### General Procedure for the Preparation of 2-Aryldiendehydrazineyl-4-phenylthiazole **2a-d**  
A solution of thiosemicarbazone **1** (3 mmol) with bromoacetophenone (3 mmol, 0.60 g) or bromoacetylcournarin (3 mmol, 0.80 g) was stirred under reflux for 1.5 h in 15 mL of THF. Reaction mixture was cooled to room temperature and poured into ice water, and the precipitate formed was filtered off and recrystallized from the appropriate solvent. 4-((2-(4-phenylthiazole-2-yl)hydrazono)methyl)benzene-1,3-diol (**2a**) was prepared from bromoacetophenone and **1a** (0.63 g). White powder. Yield 74% (0.69 g), m.p. 232-225 \({}^{\circ}\)C (EtOH:H\({}_{2}\)O 3:1) (lit. 227-228 \({}^{\circ}\)C [37]). \({}^{1}\)H NMR (DMSO-d\({}_{6}\), \(\delta\), ppm, \({}^{3}\)\({}_{\rm HH}\), Hz): 8.83 s (1H, CH=N), 7.77 d (\(J\) = 9.0, 2H, Har), m 7.47-7.32 (4H, Har); 7.29 s (1H, CH, thiazole); 6.36-6.31 dd (\({}^{3}\)\({}_{J}\) = 8.0 Hz, \({}^{4}\)\(J\) = 2.0 Hz), 6.35 d (\({}^{4}\)\(J\) = 2.0 Hz, 1H, Har). \({}^{13}\)C NMR (DMSO-d\({}_{6}\), \(\delta\), ppm): 191.5, 169.0, 165.6, 163.7, 133.4, 131.3, 129.9, 129.8, 129.1, 115.7, 110.7, 109.1, 107.6, 102.7. FT-IR, \(\upsilon\), cm\({}^{-1}\): 3228 (O-H), 1615 (C=N), 1511, 1314, 1241, 1165 (C-O). Calc., %: C, 61.72; H, 4.21; N, 13.50; S, 10.30. Found %: C 61.68, H 4.27, N 13.55, S 10.33. 2,6-di-_tert_-butyl-4-((2-(4-phenylthiazole-2-yl)hydrazineylidene)methyl)phenol **(2b)** prepared from bromoacetophenone and **1c** (0.92 g). Yellow solid. Yield 71% (0.87 g), m.p. 166-167 \({}^{\circ}\)C (EtOH: H\({}_{2}\)O 3:1). NMR \({}^{1}\)H (DMSO-d\({}_{6}\), \(\delta\), ppm, \({}^{3}\)\({}_{\rm HH}\), Hz): 11.91 s (1H, NH), 7.97 s (1H, CH=N), 7.87 d (2H, Har, \(J\) = 6.0), 7.46 s (2H, Har), 7, 44 t (2H, Har, \(J\) = 6.0), 7.30 s (1H, OH), 7.25 s (2H, Har), 1.42 (s, 18H, 2(CH\({}_{3}\))\({}_{3}\)): NMR\({}^{13}\)C (DMSO-d\({}_{6}\), \(\delta\), ppm): 169.0, 155.9, 142.9, 139.7, 135.3, 129.0, 128.4, 127.9, 126.4, 126.0 123.5, 103.7, 35.0, 30.6. FT-IR, v, cm\({}^{-1}\): 3673 (O-H), 1577 (C=N), 1365 (C-H Ar). Calc., %: C, 70.73; H, 7.17; N, 10.31; S, 7.87. Found %: C, 70.81; H, 7.28; N, 10.25; S, 7.92. 4,6-di-_tert_-butyl-3((2-(4-phenylthiazol-2-yl)hydrazineylidene)methyl)benzene-1,2-diol (**2c**) prepared from bromoacetophenone and **1d** (0.97 g). Yellow solid. Yield 70% (0.89 g), m.p. 191-193 \({}^{\circ}\)C (EtOH: H\({}_{2}\)O 2:1). \({}^{1}\)H NMR (DMSO-d\({}_{6}\), \(\delta\), ppm, \({}^{3}\)\({}_{\rm HH}\), Hz): 8 11.44 s (1H, OH), 9.03 s (1H, CH), 7.82 d (2H, Ar, \(J\) = 9.0), 7.37 t (2H, Ar, \(J\) = 9.0), 7.33 s (1H, H-C-S), 7.27 m (1H, Har), 6.77 s (1H, Har), 1.38 s (9H, t-Bu), 1.33 s (9H, t-Bu). NMR\({}^{13}\)C (DMSO-d\({}_{6}\), \(\delta\), ppm): 189.1, 166.5, 155.8, 147.1, 143.9, 142.4, 138.1, 135.6, 135.0, 132.3, 129.8, 126.4, 114.3, 113.8, 35.5, 35.2, 32.8, 29.6. FT-IR, v, cm\({}^{-1}\): 3375 (O-H), 1621 (C=C), 1588 (C=N), 1417 (=C-H), 1364 (C-H Ar). Calc., %: C, 68.06; H, 6.90; N, 9.92; S, 7.57. Found, %: C, 68.02; H, 7.02; N, 9.82; S, 7.53. 3-(2-(2-(2,4-dihydroxybenzylidene)hydrazineyl)thiazol-4-yl)-2H-chromen-2-one (**2d**) prepared from bromoacetylcoumarin and **1a** (0.63 g). Yellow solid. Yield 90% (1.02 g), m.p. 278-280 \({}^{\circ}\)C (EtOH). NMR \({}^{1}\)H (DMSO-d\({}_{6}\), \(\delta\), ppm, \({}^{3}\)\({}_{\rm HH}\), Hz): 11.96 s (1H, NH), 10.08 s (1H, OH), 9.81 s (1H, OH), 8.53 s (1H, CH-S), 8.24 s (1H, CH=N), 7.86 d (\(J\) = 9, 1H, Har), 7.73 s (1H, Har coumarin), 7.64 t (\(J\) = 9, 1H, Har), 7.46-7.35 m (3H, Har), 6.33 s (2H, Har). \({}^{13}\)C NMR (DMSO-d\({}_{6}\), \(\delta\), ppm): 167.9, 160.6, 159.2, 158.2, 144.5, 141.8, 138.6, 132.1, 129.3, 128.6, 121.0, 119.7, 116.3, 112.0, 110.4, 108.4, 102.9, 56.5. FT-IR, v, cm\({}^{-1}\): 3601 (O-H), 3213 (N-H), 1716 (C=O), 1627 (C=C), 1504 (C=N), 1095 (C-O). Calc., %: C, 60.15; H, 3.45; N, 11.08; S, 8.45. Found, %: C, 60.01; H, 3.55; N, 11.12; S, 8.41. 3-(2-(2-(4,6-di-_tert_-butyl-2,3-dihydroxybenzylidene)hydrazineyl)thiazol-4-yl)-2H-chromen-2-one (**2e**) prepared from bromoacetylcoumarin and **1c** (0.92 g). White solid.