Synthesis of compound 12 Concentrated sulfuric acid (64 mmol) was added Bortezomib clinical trial into compound 9 (10 mmol) drop by drop under stirring, and the reaction content was stirred in an ice bath for 15 min. The precipitated product was filtered, washed with water, and recrystallized from ethanol to afford the desired product. 5-[(6-Morpholin-4-ylpyridin-3-yl)methyl]-N-phenyl-1,3,4-thiadiazol-2-amine (12) Yield (2.13 g, 58 %); m.p. 172–173 °C; IR (KBr, ν, cm−1): 3,252 (2NH), 3,077 (Ar CH), 1,599 (C=N), 1,121 (C–O); 1H NMR (DMSO-d 6, δ ppm): 3.49 (bs, 4H, N–2CH2), 3.66 (bs, 4H, O–2CH2), 4.49 (s, 2H, CH2), 6.04 (bs, 1H, NH), 7.26–7.34 (m, 4H, arH), 7.54–7.66 (m, 4H, arH), 10.23 (s,1H, NH); 13C NMR (DMSO-d 6, δ ppm): 34.63 (CH2), 47.18 (N–2CH2), 66.69 (O–2CH2), arC: [109.13 (CH), 117.93 (2CH), 122.42 (2CH), 125.33 (CH), 129.75 (2CH), 137.53 (C), 141.31 (C), 153.50 (C)], 161.75 (thiadiazole C-2), 165.11 (thiadiazole C-5); LC–MS:
m/z (%) 368.45 [M]+ (56), 165.45 (85); Anal.calcd (%) for C18H20N6OS: C, 58.68; H, 5.47; N, 22.81, S, 8.70. Found: C, 58.74; H, 5.55; N, 22.85; S, 8.75. Synthesis of compound 13 Ethyl bromoacetate was added to the solution of compound 9 in absolute ethanol (10 mmol), and the mixture was refluxed in the presence of dried sodium acetate (16.4 g 200 mmol) for 9 h. Then, the mixture was cooled to room temperature, poured into ice-cold water under stirring, and left overnight BMS-354825 in vivo in cold. The formed solid was filtered, washed with water three
times, and recrystallized from benzene-petroleum ether (1:2) to afford the pure compound. 2-[(6-Morpholin-4-ylpyridin-3-yl)amino]-N’-(4-oxo-3-phenyl-1,3-thiazolidin-2-ylidene)acetohydrazide (13) Yield (3.33 g, 45 %); m.p. 201–202 °C; IR (KBr, ν, cm−1): 3,326 (2NH), 1,746 (2C=O), 1,492 (C=N), 1,119 (C–O); 1H NMR (DMSO-d 6, δ ppm): 3.17 (bs, 4H, N–2CH2), 3.67 (bs, 4H, O–2CH2), 3.86 (d, 2H, CH2, J = 3.8 Hz), 4.18 (s, 2H, S–CH2), 5.74 (bs, 1H, NH), 6.89–7.16 (m, 5H, arH), 7.32–7.38 (m, 3H, arH), 10.86 (s, Rebamipide 1H, NH); 13C NMR (DMSO-d 6, δ ppm): 30.61 (NH–CH2), 45.58 (thiazolidine-CH2), 56.28 (N–2CH2), 66.64 (O–2CH2), arC: [107.12 (CH), 108.79 (CH), 121.52 (CH), 124.15 (CH), 125.19 (CH), 126.52 (C), 129.52 (CH), 130.02 (CH), 132.84 (CH), 138.32 (C), 148.02 (C)], 152.30 (thiazolidine C-2), 158.39 (thiazolidine C-4), 170.94 (C=O); LC–MS: m/z (%) 426.52 [M]+ (52), 215.86 (64), 165.42 (74); Anal.calcd (%) for C20H22N6O3S: C, 56.32; H, 5.20; N, 19.70, S, 7.52. Found: C, 56.42; H, 5.32; N, 19.65; S, 7.62.