3.1.3. General Procedure for the Synthesis of 5-Benzyliden-2-(5-methylthiazol-2-ylimino) thiazolidin-4-one

To a solution of 2-[5-methylthiazol-2-yl)-thiazolidin-4-one (0.35 g, 0.001 mol) in CH₃COOH (17 mL) buffered with CH₃COONa (0.16 g, 0.002 mol,) was added an adequate benzaldehyde (0.0015 mol). The mixture was refluxed for 4 h and then drained on ice-H₂O. The obtained solid was recovered by filtration and washed with H₂O. It was recrystallized from absolute C₂H₅OH or dioxane.

This compound was published in our previous paper [48].

Yield: 98%, mp. 215–216 °C (dioxane); IR (cm⁻¹): 1720 (carbonyl), 2352 (-N-H amide), 2720 (OH); ¹H-NMR (DMSO-d₆ ; 300 MHz) δ: 2.33 (s, 3H, -CH₃), 6.74 (s, 1H, OH), 7.13–7.26 (m, 3H, Ar), 7.38 (s, 1H, -CH-N), 7.42–7.51 (m, 2H, Ar, =C-H) 7.88 (s, 1H, -N-H); ¹³C-NMR (CDCl₃; 125 MHz) δ ppm: δ: 11.81, 116.02, 116.75, 117.73, 121.22, 128.95, 192.21, 130.84, 137.01, 143.02, 157.13, 158.24, 171.02, 174.23. Anal. Calcd. for C₁₄H₁₁N₃O₂S₂ (%): C, 52.98; H, 3.49; N, 13.24; O, 10.08; S, 20.21. Found (%): C, 52.95; H, 3.46; N, 13.22.

Yield: 42.8%, mp. 210–211 °C (dioxane); IR. (cm⁻¹): 1738 (carbonyl), 2360 (-N-H amide), 2725 (OH); ¹H-NMR (DMSO-d₆ ; 300 MHz) δ. 2.34 (s, 3H, -CH₃), 6.93 (s, 1H, Ar), 7.21–7.69 (m, 5H, 3Ar, -CH thiazole, =C-H), 10.31 (s, 1H, -O-H), 11.96 (s, 1H, -N-H); ¹³C-NMR (CDCl₃; 125 MHz) δ ppm: 11.82, 115.03, 116.12, 127.91, 130.68, 131.12, 138.71, 143.03, 157.77, 158.02, 171.03, 174.19. Anal. Calcd. for C₁₄H₁₁N₃O₂S₂ (%): C, 52.98; H, 3.49; N, 13.24; O, 10.08; S, 20.21. Found (%): C, 52.96; H, 3.44; N, 13.23.

Yield: 35%, mp. 205–206 °C (dioxane); IR (cm⁻¹): 1720 (carbonyl), 2380 (-N-H amide); ¹H-NMR (DMSO-d₆ ; 300 MHz) δ: 2.33 (s, 3H, -CH₃), 3.88 (s, 3H, -CH₃O), 6.97–7.23 (m, 3H, -CH thiazole, 2 Ar), 7.34–7.66 (m,3H, =C-H, Ar), 7.79 (s,1H, NH); ¹³C-NMR (CDCl₃; 125 MHz) δ ppm: 11.80, 58.86, 114.23, 116.11, 127.91, 130.05, 131.12, 138.64, 143.15, 158.02, 159.83, 171.03, 174.22. Anal. Calcd. For C₁₅H₁₃N₃O₂S₂ (%): C, 54.36; H, 3.95; N, 12.68; O, 9.66; S, 19.35. Found (%): C, 54.35; H, 3.96; N, 12.61

Yield: 30%, mp. 200–201 °C (dioxane), R_f = 0.55 (PhCH_3:C₂H₅OH 8:2), IR (cm⁻¹): 1715 (carbonyl), 2406 (-N-H amide); ¹H-NMR (DMSO-d₆ ; 300 MHz) δ: 2.34 (s, 3H, -CH₃), 3.75 (s, 6H, -CH₃-O), 6.98–7.22 (m, 3H, 2 Ar, -CH thiazole), 7.32–7.45 (m, 2H, =C-H, Ar), 7.83 (s, 1H, -N-H). ¹³C-NMR (CDCl₃; 125 MHz) δ ppm: 19.24, 56.2, 57.12, 11.17, 114.36, 115.93, 117.96, 118.85, 143.18, 150.23, 151.11, 151.96, 152.87, 158.34, 168.05, 173.67. Anal. Calcd. For C₁₆H₁₅N₃O3S₂ (%): C, 53.17; H, 4.18; N, 11.63; O, 13.28; S, 17.74. Found (%): C, 53.15; H, 4.14; N, 11.61.

This compound was published in our previous paper [48].

This compound was published in our previous paper [48].

This compound was published in our previous paper [48].

Yield: 39%, mp. 178–179 °C (dioxane), R_f = 0.77 (PhCH_3:C₂H₅OH 8:2), IR (cm⁻¹): 1597 (carbonyl), 3050 (-N-H amide); ¹H-NMR (DMSO-d₆; 300 MHz) δ: 2.36 (s, 3H, -CH₃), 7.31–7.45 (μ, 3H, H-3, H-5, -CH thiazole), 7.63–7.75 (m, 3H, 2 Ar, =C-H), 12.55 (s, 1H, -N-H). ¹³C-NMR (CDCl₃; 125 MHz) δ ppm: 11.81, 115.23, 116.71, 127.51, 130.04, 132.12, 138.64, 143.15, 158.72, 162.04, 171.03, 174.21. Anal. Calcd. For C₁₄H₁₀FN₃OS₂ (%): C, 52.65; H, 3.16; F, 5.95; N, 13.16; O, 5.01; S, 20.08. Found (%): C, 52.62; H, 3.15; N, 13.12.

This compound was published in our previous paper [48].

Yield: 61.7%, mp. 249–250 °C (dioxane), R_f = 0.60 (PhCH_3:C₂H₅OH 8:2), IR: (cm⁻¹, Nujol), 1709 (carbonyl), 2724 (N-H amide), 721 (-C-Cl); ¹H-NMR (DMSO-d₆ ; 300 MHz) δ: 2.36 (s, 3H, -CH₃), 7.33 (s, 1H, -CH thiazole), 7.56–7.61 (m, 3H, Ar), 7.71 (s, 1H, =C-H), 7.79 (s, 1H, -N-H). ¹³C-NMR (CDCl₃; 125 MHz) δ ppm: 19.31, 114.17, 125.12, 128.14, 128.92, 129.76, 133.16, 141.11, 143.91, 150.44, 150.48, 159.67, 168.11, 173.26. Anal. Calcd. For C₁₄H₉Cl₂N₃OS₂ (%): C, 45.41; H, 2.45; Cl, 19.15; N, 11.35; O, 4.32; S, 17.32. Found (%): C, 45.38; H, 2.42; N, 11.31.

Yield: 57.7%, mp. 260–261 °C (dioxane), R_f = 0.77 (PhCH_3:C₂H₅OH 8:2), IR: (cm⁻¹, Nujol), 1729 (carbonyl), 3049 (N-H amide), 720 (-Cl-C); ¹H-NMR (DMSO-d₆ ; 300 MHz) δ: 2.36 (s, 3H, -CH₃), 7.43 (s, 1H, -CH thiazole), 7.53–7.79 (m, 4H, 3 Ar, =C-H), 12.73 (s, 1H, -N-H). ¹³C-NMR (CDCl₃; 125 MHz) δ ppm: 11.94, 116.15, 125.27, 126.03, 129.11, 130.14, 131.17 (2C), 136.27, 138.56, 143.33, 158.26, 168.55, 174.28. Anal. Calcd. For C₁₄H₉Cl₂N₃OS₂ (%) : C, 45.41; H, 2.45; Cl, 19.15; N, 11.35; O, 4.32; S, 17.32. Found (%): C, 45.36; H, 2.43; N, 11.30.

Yield: 94.6%, mp. 225–226 °C (dioxane), R_f = 0.60 (PhCH_3:C₂H₅OH 8:2), IR: (cm⁻¹, Nujol), 1600 (carbonyl), 2359 (-N-H amide), 722 (-Cl-C); ¹H-NMR (DMSO-d₆ ; 300 MHz) δ: 2.36 (s, 3H, -CH₃), 7.33 (s, 1H, -CH thiazole), 7.54–7.60 (m, 3H, 3 Ar), 7.71 (s, 1H, =C-H), 7.77 (s, 1H, -N-H). ¹³C-NMR (CDCl₃; 125 MHz) δ ppm: 11.17, 116.14, 126.20, 127.85 (2C), 129.14 (2C), 130.52, 132.78, 135.22, 138.01, 143.29, 157.93, 168.73, 174.26. Anal. Calcd. For C₁₄H₉Cl₂N₃OS₂ (%): C, 45.41; H, 2.45; Cl, 19.15; N, 11.35; O, 4.32; S, 17.32. Found (%): C, 45.37; H, 2.40; N, 11.31.

Yield: 28.8%, mp. 220–221 °C (dioxane), R_f = 0.57 (PhCH_3:C₂H₅OH 8:2), IR: (cm⁻¹, Nujol), 1704 (carbonyl), 2356 (N-H amide); ¹H-NMR (DMSO-d₆ ; 300 MHz) δ: 2.36 (s, 3H, -CH₃), 7.43 (s, 1H, -CH thiazole), 7.48–7.83 (m, 4H, Ar), 7.89 (s, 1H, =C-H), 12.53 (s, br, 1H, -N-H). ¹³C-NMR (CDCl₃; 125 MHz) δ ppm: 11.15, 116.11, 123.28, 126.87, 128.53, 129.15, 130.77, 131.93, 137.18, 138.06, 142.61, 158.14, 168.79, 174.12. Anal. Calcd. For C₁₄H₁₀BrN₃OS₂ (%): C, 44.22; H, 2.65; Br, 21.01; N, 11.05; O, 4.21; S, 16.86. Found (%): C, 44.18; H, 2.61; N, 10.97.

Yield: 57.0%, mp. 259–260 °C (dioxane), R_f = 0.53 (PhCH_3:C₂H₅OH 8:2), IR: (cm⁻¹, Nujol), 1711 (carbonyl), 3249 (-N-H amide). ¹H-NMR: (δ, DMSO-d_6, 300 MHz 2.2 (s, 3H, -CH₃), 7.36 (d, 2H, -CH thiazole, =CH), 7.55–7.77 (m, 4-H, Ar), 12.67 (s, 1H, -N-H). ¹³C-NMR (CDCl₃; 125 MHz) δ ppm: 11.16, 116.10, 123.42, 128.05 (2C), 130.19 (2C), 131.93, 135.18, 138.72, 143.01, 158.13, 168.82, 174.04. Anal. Calcd. For C₁₄H₁₀BrN₃OS₂ (%): C, 44.22; H, 2.65; Br, 21.01; N, 11.05; O, 4.21; S, 16.86. Found (%): C, 44.20; H, 2.63; N, 10.98.