Preparation of 4-(4-substituted phenyl)- 4-oxobutanoic acid (I)
Aryl derivatives (10mmol) reacted with Succinic anhydride (10mmol) by using anhydrous aluminum chloride (11.25mmol) for 6 hours at room temperature. The final product was purified using 5% Sodium hydroxide solution and filtered to remove the salts. Product was isolated by adding dilute HCl to mother liquor. The solid was filtered and purified using acetone to obtained desired colorless solid product.
General procedure for the synthesis of 5-(4-substituted phenyl)-3-{[5-(4-nitrophenyl)furan-2-yl]methylidene}furan-2(3H)-one (II)
4-(4-Substituted phenyl)- 4-oxobutanoic acidcondensed (3mmol) with 5-(4-Chloro-phenyl)-furan-2-carbardehyde (3 mmol) in acetic anhydride (15ml) and catalytic sodium acetate at reflux temperature for 4 hours and under anhydrous condition. The reaction mass quenched in cold water and filtered to obtained solid product. Crude product purified in the mixture of methanol and chloroform.
General procedure for the synthesis of 4-(4-substituted phenyl)-N-(substituted benzyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutanamide (III)
Substituted furan (II) (3 mmol) and various substituted benzylamines (4 mmol) treated at reflux temperature in benzene. After reaction completion reaction solvent was distilled under vacuum to obtained solid. Obtained solid was washed with pet ether and purified using methanol solvent.
Physical constants and Spectral characterization of synthesized compounds (1-18)
N-benzyl-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxo-4-phenylbutnamide (1);Yellow powder;Yield: 60.3%. m.p. 170-171°C. 1H NMR (500 MHz, DMSO) δ 8.27 (d, J = 8.9 Hz, 2H), 7.92 (d, J = 8.9 Hz, 2H), 7.45 (d, J = 3.6 Hz, 1H), 7.38 (d, J = 7.4 Hz, 2H), 7.31 – 7.21 (m, 4H), 7.17 – 7.10 (m, 5H), 7.04 (d, J = 3.7 Hz, 1H), 6.85 (s, 1H), 4.21 (dd, J = 97.0, 15.3 Hz, 2H), 3.49 (s, 2H). 13C NMR (126 MHz, DMSO) δ 167.75, 153.53, 152.79, 146.67, 143.75, 138.55, 135.60, 129.85, 128.69, 128.43, 128.24, 128.21, 126.92, 126.12, 125.06, 124.86, 117.58, 116.45, 113.26, 89.80, 44.72, 43.93. EM-MS: m/z 467.2 (M+1). IR (cm-1, KBr): 1654 (CO), 3308 (NH). Anal. calcd. for C28H22N2O5 : C, 72.09; H, 4.75; N, 6.01; found C,72.26; H, 4.56; N, 5.96.
N-(2-chlorobenzyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxo-4-phenylbutnamide (2);Yellow powder;Yield = 55.45%. m.p. 175-176°C. 1H NMR (500 MHz, DMSO) δ 8.28 (d, J = 8.8 Hz, 2H), 7.94 (d, J = 8.8 Hz, 2H), 7.47 (d, J = 3.6 Hz, 1H), 7.42 (d, J = 7.6 Hz, 2H), 7.32 – 7.15 (m, 8H), 7.08 (d, J = 3.6 Hz, 1H), 6.91 (s, 1H), 4.30 (dd, J = 159.5, 16.5 Hz, 2H), 3.56 (s, 2H). 13C NMR (126 MHz, DMSO) δ 168.07, 153.45, 152.93, 146.72, 143.38, 135.59, 135.29, 131.81, 129.41, 129.35, 129.12, 128.72, 128.64, 128.36, 127.20, 126.03, 125.08, 124.92, 117.87, 116.88, 113.30, 89.92, 44.68, 41.35. EM-MS: m/z 501.6 (M+1). IR (cm-1, KBr): 1617 (CO), 3290 (NH). Anal. calcd. for C28H21ClN2O5 : C, 67.14; H, 4.23; N, 5.59; found C, 67.06; H, 4.17; N, 5.89.
N-(4-fluorobenzyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxo-4-phenylbutnamide (3);Yellow powder; Yield: 55.34%. m.p. 179-180oC. 1H- NMR (500 MHz, DMSO) δ 8.26 (d, J = 8.9 Hz, 2H), 7.91 (d, J = 8.8 Hz, 2H), 7.44 (d, J = 3.6 Hz, 1H), 7.37 (d, J = 7.1 Hz, 2H), 7.31 – 7.20 (m, 4H), 7.12 (dd, J = 8.4, 5.8 Hz, 2H), 7.04 (d, J = 3.6 Hz, 1H), 6.96 (t, J = 8.9 Hz, 2H), 6.87 (s, 1H), 4.20 (dd, J = 75.2, 15.2 Hz, 2H), 3.49 (d, J = 1.7 Hz, 2H). 13C NMR (126 MHz, DMSO) δ 167.74, 162.41, 160.48, 153.50, 152.83, 146.69, 143.67, 135.60, 134.77, 130.53, 130.46, 129.74, 128.67, 128.25, 126.13, 125.05, 124.88, 117.62, 116.54, 114.95, 114.79, 113.25, 89.71, 44.73, 43.11. EM-MS: m/z 484.27 (M+). IR (cm-1, KBr): 1634 (CO), 3353 (NH). Anal. calcd. for C28H21FN2O5 : C, 69.42; H, 4.37; N, 5.78; found C,69.32; H, 4.20; N, 5.72.
N-benzyl-4-(4-fluorophenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutnamide (4);Yellow powder; Yield: 57.34%. m.p. 190-191oC. 1H- NMR (500 MHz, DMSO) δ 8.27 (d, J = 8.9 Hz, 2H), 7.93 (d, J = 8.9 Hz, 2H), 7.46 (d, J = 3.7 Hz, 1H), 7.39 (dd, J = 8.8, 5.5 Hz, 2H), 7.23 (t, J = 2.4 Hz, 1H), 7.18 – 7.00 (m, 8H), 6.92 (s, 1H), 4.23 (q, J = 15.3 Hz, 2H), 3.50 (d, J = 2.0 Hz, 2H). 13C NMR (126 MHz, DMSO) δ 167.72, 163.03, 161.09, 153.51, 152.83, 146.67, 139.84, 138.54, 135.59, 129.63, 128.49, 128.40, 128.22, 126.94, 125.05, 124.89, 117.66, 116.59, 115.33, 115.16, 113.27, 89.34, 44.59, 43.66. EM-MS: m/z 485.50 (M+1). IR (cm-1, KBr): 1653 (CO), 3317 (NH). Anal. calcd. for C28H21FN2O5 : C, 69.42; H, 4.37; N, 5.78; found C,69.32; H, 4.30; N, 5.68.
N-(2-chlorobenzyl)-4-(4-fluorophenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutnamide (5);Yellow powder;Yield: 60.78%. m.p. 192-193oC. 1H- NMR (400 MHz, DMSO) δ 8.28 (d, J = 8.7 Hz, 2H), 7.95 (d, J = 8.7 Hz, 2H), 7.51 – 7.39 (m, 3H), 7.21 (dtt, J = 10.0, 7.5, 3.9 Hz, 5H), 7.07 (dd, J = 15.6, 6.4 Hz, 3H), 6.97 (s, 1H), 4.33 (dd, J = 92.3, 16.4 Hz, 2H), 3.55 (d, J = 1.9 Hz, 2H). 13C NMR (101 MHz, DMSO) δ 168.05, 163.27, 160.85, 153.43, 152.96, 146.72, 139.47, 135.58, 135.26, 131.87, 129.55, 129.23, 129.12, 128.70, 128.46, 128.37, 127.22, 125.07, 124.94, 117.92, 116.99, 115.38, 115.17, 113.29, 89.45, 44.57, 41.01. EM-MS: m/z 520.13 (M+2). IR (cm-1, KBr): 1609 (CO), 3275 (NH). Anal. calcd. for C28H20ClFN2O5 : C, 64.81; H, 3.88; N, 5.40; found C,64.66; H, 3.76; N, 5.32.
N-(4-flurobenzyl)-4-(4-flurophenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutnamide (6);Yellow powder; Yield: 62.89%. m.p. 203-204oC. 1H- NMR (500 MHz, DMSO) δ 8.26 (t, J = 6.3 Hz, 2H), 7.92 (t, J = 6.1 Hz, 2H), 7.48 – 7.42 (m, 1H), 7.38 (dd, J = 8.0, 6.0 Hz, 2H), 7.24 (s, 1H), 7.16 – 7.02 (m, 5H), 7.00 – 6.92 (m, 3H), 4.22 (q, J = 15.2 Hz, 2H), 3.49 (s, 2H). 13C NMR (126 MHz, DMSO) δ 167.71, 163.05, 162.41, 161.11, 160.48, 153.47, 152.85, 146.67, 139.78, 135.57, 134.78, 134.75, 130.50, 130.43, 129.51, 128.49, 128.43, 125.04, 124.89, 117.70, 116.67, 115.34, 115.17, 114.98, 114.81, 113.26, 89.28, 79.63, 44.60, 42.87. EM-MS: m/z 504.07(M+1). IR (cm-1, KBr): 1617 (CO), 3279 (NH). Anal. calcd. for C28H20F2N2O3 : C, 66.93; H, 4.01; N, 5.58; found C,66.53; H, 3.92; N, 5.48.
N-benzyl-4-(4-chlorophenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutnamide (7);
Yellow powder; Yield: 50.74%. m.p. 150-151oC. 1H- NMR (500 MHz, DMSO) δ 8.28 (d, J = 8.8 Hz, 2H), 7.94 (d, J = 8.8 Hz, 2H), 7.4 – 7.39 (m, 3H), 7.33 – 7.24 (m, 4H), 7.17 – 7.10 (m, 5H), 7.06 (d, J = 3.6 Hz, 1H), 4.30 (dd, J = 159.5, 16.5 Hz, 2H), 3.56 (s, 2H). 13C NMR (126 MHz, DMSO) δ 167.53, 153.70, 152.77, 146.67, 143.68, 138.36, 135.55, 131.41, 129.20, 128.71, 128.38, 128.29, 126.85, 126.07, 125.20, 124.70, 117.53, 116.52, 113.37, 89.36, 44.93, 43.72. EM-MS: m/z 502.7 (M+ 1). IR (cm-1, KBr): 1638 (CO), 3332 (NH). Anal. calcd. for C28H21ClN2O5 : C, 67.41; H, 4.23; N, 5.59; found C,67.32; H, 4.15; N, 5.56.
N-(2-chlorobenzyl)-4-(4-flurophenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutnamide (8);Yellow powder;Yield: 71.34%. m.p. 160-161oC. 1H- NMR (500 MHz, DMSO) δ 8.26 (t, J = 7.1 Hz, 2H), 7.93 (t, J = 7.1 Hz, 2H), 7.44 (dd, J = 20.6, 6.4 Hz, 3H), 7.33 – 7.23 (m, 5H), 7.19 (dt, J = 13.7, 6.8 Hz, 2H), 7.07 (d, J = 3.5 Hz, 1H), 7.02 (s, 1H), 4.33 (dd, J = 125.4, 16.4 Hz, 2H), 3.55 (s, 2H). 13C NMR (126 MHz, DMSO) δ 168.06, 153.39, 152.98, 146.68, 142.31, 135.55, 135.22, 133.00, 131.90, 129.57, 129.13, 129.04, 128.70, 128.55, 128.16, 127.23, 125.01, 124.93, 117.95, 117.07, 113.27, 89.45, 44.47, 41.10. EM-MS: m/z 536 (M+1). IR (cm-1, KBr): 1613 (CO), 3355 (NH). Anal. calcd. for C28H20Cl2N2O5: C, 62.82; H, 3.77; N, 5.23; found C, 62.23; H, 3.88; N, 5.39.
4-(4-chlorobenzyl)-N-(4-flurobenzyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutnamide (9);Yellow powder; Yield: 67.90%. m.p. 175-176oC. 1H- NMR (600 MHz, DMSO) δ 8.29 (d, J = 8.8 Hz, 2H), 7.94 (d, J = 8.8 Hz, 2H), 7.49 (d, J = 3.6 Hz, 1H), 7.35 (dd, J = 28.0, 8.6 Hz, 4H), 7.25 (t, J = 2.3 Hz, 1H), 7.13 (dd, J = 8.3, 5.8 Hz, 2H), 7.09 (d, J = 3.6 Hz, 1H), 7.02 (s, 1H), 6.99 (t, J = 8.8 Hz, 2H), 4.22 (dd, J = 44.3, 15.3 Hz, 2H), 3.50 (s, 2H). 13C NMR (151 MHz, DMSO) δ 167.69, 162.23, 160.63, 153.41, 152.87, 146.62, 142.58, 135.53, 134.72, 134.70, 132.91, 130.46, 130.40, 129.28, 128.54, 128.23, 125.08, 124.90, 117.86, 116.72, 115.00, 114.86, 113.32, 89.23, 44.43, 42.89. EM-MS: m/z 519.4 (M+1). IR (cm-1, KBr): 1650 (CO), 3332 (NH). Anal. calcd. for C28H20Cl2FNO3 : C, 64.81; H, 3.88; N, 5.40; found C,64.87; H, 3.93; N, 5.58.
N-benzyl-4-(4-bromophenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutnamide (10); Yellow powder;Yield: 61.32%. m.p. 178-179oC. 1H- NMR (500 MHz, DMSO) δ 8.29 (d, J = 8.8 Hz, 2H), 7.94 (d, J = 8.8 Hz, 2H), 7.47 – 7.39 (m, 3H), 7.33 – 7.27 (m, 4H), 7.24 – 7.06 (m, 5H), 7.05 (d, J = 3.6 Hz, 1H), 4.31 – 4.11 (m, 2H), 3.51 (s, 2H). 13C NMR (126 MHz, DMSO) δ 167.82, 153.48, 152.79, 146.67, 143.68, 138.47, 135.58, 131.48, 129.78, 128.71, 128.37, 128.23, 126.95, 126.07, 125.04, 124.86, 117.60, 116.51, 113.22, 89.84, 44.72, 43.93. EM-MS: m/z 545.13 (M +). IR (cm-1, KBr): 1619 (CO), 3326 (NH). Anal. calcd for C28H21BrN2O5 : C, 61.66; H, 3.88; N, 5.14; found C,61.56; H, 3.95; N, 5.32.
4-(4-bromophenyl)-N-(2-chlorophenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutanamide (11); Yellow powder; Yield: 45.56%. m.p. 171-172oC. 1H- NMR (500 MHz, DMSO) δ 8.27 (d, J = 8.6 Hz, 2H), 7.93 (d, J = 8.6 Hz, 2H), 7.45 (d, J = 6.9 Hz, 3H), 7.39 – 7.08 (m, 8H), 7.07 (d, J = 3.1 Hz, 1H), 4.33 (dd, J = 160.5, 16.5 Hz, 2H), 3.62 – 3.53 (m, 2H). 13C NMR (151 MHz, DMSO) δ 168.07, 153.40, 153.35, 152.96, 152.89, 146.59, 143.36, 142.74, 135.52, 135.24, 135.16, 131.84, 131.75, 131.51, 129.47, 129.29, 129.25, 129.11, 128.94, 128.74, 128.64, 128.49, 128.38, 127.21, 126.03, 125.05, 124.90, 124.85, 121.68, 118.04, 117.93, 117.06, 116.88, 113.31, 89.92, 89.52, 44.66, 41.39. EM-MS: m/z 580.27 (M+1). IR (cm-1, KBr): 1645 (CO), 3288 (NH). Anal. calcd. for C28H20BrClN2O3 : C, 58.00; H, 3.48; N, 4.83; found C,58.05; H, 3.52; N, 4.95.
4-(4-bromophenyl)-N-(4-fluorobenzyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutanamide (12); Yellow powder; Yield: 47.78%. m.p. 167-168oC. 1H- NMR (500 MHz, DMSO) δ 8.28 (d, J = 8.3 Hz, 2H), 7.93 (d, J = 8.7 Hz, 2H), 7.50 – 7.18 (m, 7H), 7.17 – 7.02 (m, 3H), 6.95 (dd, J = 32.8, 25.2 Hz, 3H), 4.33 – 4.10 (m, 2H), 3.50 (s, 2H). 13C NMR (126 MHz, DMSO) δ 167.74, 153.50, 152.82, 146.69, 143.67, 143.08, 130.53, 130.46, 129.74, 128.67, 128.55, 126.13, 125.04, 124.87, 117.61, 116.54, 114.95, 114.78, 113.24, 89.71, 44.73, 43.11. EM-MS: m/z 564.6 (M+1). IR (cm-1, KBr): 1628 (CO), 3338 (NH). Anal. calcd. for C28H20BrFN2O5: C, 59.69; H, 3.58; N, 4.79; found C, 59.78; H, 3.79; N, 5.71.
N-benzyl-4-(4-methoxyphenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutanamide (13); Yellow powder; Yield: 58.60%. m.p. 192-193oC. 1H- NMR (600 MHz, DMSO) δ 8.28 (d, J = 8.8 Hz, 2H), 7.92 (d, J = 8.8 Hz, 2H), 7.48 (d, J = 3.6 Hz, 1H), 7.31 (d, J = 8.7 Hz, 2H), 7.28 – 7.11 (m, 6H), 7.06 (d, J = 3.6 Hz, 1H), 6.92 – 6.80 (m, 3H), 4.21 (dd, J = 118.4, 15.3 Hz, 2H), 3.72 (s, 3H), 3.49 (s, 2H). 13C NMR (151 MHz, DMSO) δ 167.65, 159.21, 153.55, 152.74, 146.58, 138.66, 135.64, 135.58, 129.99, 128.38, 128.24, 127.45, 126.92, 125.08, 124.81, 117.60, 116.33, 113.96, 113.31, 89.72, 55.55, 44.75, 43.83. EM-MS: m/z 497.3 (M+1). IR (cm-1, KBr): 1638 (CO), 3325 (NH). Anal. calcd. for C29H24N2O5: C, 70.15; H, 4.87; N, 5.64; found C,70.29; H, 4.78; N, 5.77.
N-(2-chlorobenzyl)-4-(4-methoxyphenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutanamide (14); Yellow powder; Yield: 53.78%. m.p. 195-196oC. 1H- NMR (600 MHz, DMSO) δ 8.28 (d, J = 8.8 Hz, 2H), 7.93 (d, J = 8.8 Hz, 2H), 7.49 (d, J = 3.6 Hz, 1H), 7.32 (t, J = 8.3 Hz, 4H), 7.28 – 7.19 (m, 3H), 7.12 (d, J = 8.1 Hz, 2H), 7.08 (d, J = 3.6 Hz, 1H), 6.92 (s, 1H), 4.21 (dd, J = 118.4, 15.3 Hz, 2H), 3.73 (s, 3H), 3.49 (s, 2H). 13C NMR (151 MHz, DMSO) δ 167.98, 161.95, 153.39, 152.85, 146.57, 137.56, 135.50, 135.25, 131.71, 129.38, 129.31, 129.12, 129.10, 127.20, 125.91, 125.03, 124.81, 117.87, 116.76, 113.28, 89.97, 56.84, 44.69, 41.51. EM-MS: m/z 532.21 (M+1). IR (cm-1, KBr): 1610 (CO), 3317 (NH). Anal. calcd. for C29H23ClN2O6: C, 65.60; H, 4.37; N, 5.28; found C, 65.66; H, 4.42; N, 5.18.
N-(4-fluorobenzyl)-4-(4-methoxyphenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutanamide (15); Yellow powder; Yield: 66.33%. m.p. 201-202oC. 1H- NMR (600 MHz, DMSO) δ 8.29 (d, J = 8.9 Hz, 2H), 7.93 (d, J = 8.9 Hz, 2H), 7.48 (s, 1H), 7.26 (d, J = 8.1 Hz, 2H), 7.22 – 7.02 (m, 8H), 6.99 (d, J = 3.6 Hz, 1H), 6.86 (s, 1H), 4.18 (dd, J = 157.4, 15.4 Hz, 2H), 3.87 (s, 3H), 3.47 (s, 2H). 13C NMR (151 MHz, DMSO) δ 167.70, 161.99, 160.55, 156.83, 153.61, 152.89, 146.62, 140.84, 137.51, 135.57, 130.57, 130.52, 129.83, 129.31, 126.09, 125.18, 124.78, 117.90, 116.33, 114.98, 114.84, 113.42, 89.85, 56.63, 44.87, 41.60. EM-MS: m/z 514.2 (M+). IR (cm-1, KBr): 1657 (CO), 3317 (NH). Anal. calcd. for C29H23FN2O6 : C, 67.70; H, 4.51; N, 5.44; found C, 67.50; H, 4.55; N, 5.80.
N-benzyl-4-(4-methylphenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutanamide (16); Yellow powder; Yield: 56.56%. m.p. 215-216oC. 1H- NMR (600 MHz, DMSO) δ 8.27 (d, J = 8.9 Hz, 2H), 7.91 (d, J = 8.9 Hz, 2H), 7.47 (d, J = 3.6 Hz, 1H), 7.28 (d, J = 8.1 Hz, 2H), 7.24 – 7.10 (m, 8H), 7.05 (d, J = 3.6 Hz, 1H), 6.85 (s, 1H), 4.20 (dd, J = 157.4, 15.4 Hz, 2H), 3.49 (dd, J = 7.5, 1.8 Hz, 2H), 2.26 (s, 3H). 13C NMR (151 MHz, DMSO) δ 167.67, 153.51, 152.74, 146.56, 140.86, 138.61, 137.47, 135.55, 129.89, 129.28, 128.37, 128.22, 126.90, 126.02, 125.06, 124.79, 117.61, 116.34, 113.29, 89.85, 44.73, 43.96, 21.07. EM-MS: m/z 481.2 (M+1). IR (cm-1, KBr): 1623 (CO), 3234 (NH). Anal. calcd. for C29H24N2O5: C, 72.49; H, 5.03; N, 5.83; found C,72.28; H, 5.14; N, 5.75.
N-(2-chlorobenzyl)-4-(4-methylphenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutanamide (17); Yellow powder; Yield: 55.13%. m.p. 189-190oC. 1H- NMR (600 MHz, DMSO) δ 8.28 (d, J = 8.8 Hz, 2H), 7.93 (d, J = 8.8 Hz, 2H), 7.49 (d, J = 3.6 Hz, 1H), 7.32 (t, J = 8.3 Hz, 4H), 7.28 – 7.18 (m, 3H), 7.12 (d, J = 8.1 Hz, 2H), 7.08 (d, J = 3.6 Hz, 1H), 6.92 (s, 1H), 4.28 (dd, J = 212.2, 16.7 Hz, 2H), 3.55 (qd, J = 19.3, 2.3 Hz, 2H), 2.25 (s, 3H). 13C NMR (151 MHz, DMSO) δ 168.01, 153.42, 152.88, 146.60, 140.54, 137.59, 135.53, 135.28, 131.74, 129.41, 129.34, 129.15, 129.13, 128.60, 127.23, 125.94, 125.06, 124.84, 117.89, 116.79, 113.31, 90.00, 44.72, 41.54, 21.07. EM-MS: m/z 515.23 (M+1). IR (cm-1, KBr): 1655 (CO), 3314 (NH). Anal. calcd. for C29H23ClN2O5: C, 67.64; H, 4.50; N, 5.44; found C,67.69; H, 4.60; N, 5.30.
N-(4-fluorobenzyl)-4-(4-methylphenyl)-2-{[5-(4-nitrophenyl)furan-2-yl]methylidene}-4-oxobutanamide (18); Yellow powder; Yield: 70.14%. m.p. 205-206oC. 1H- NMR (600 MHz, DMSO) δ 8.29 (d, J = 8.3 Hz, 2H), 7.93 (d, J = 8.3 Hz, 2H), 7.48 (s, 1H), 7.32 – 7.19 (m, 3H), 7.19 – 7.09 (m, 4H), 7.06 (s, 1H), 7.00 (t, J = 8.6 Hz, 2H), 6.86 (s, 1H), 4.18 (dd, J = 132.5, 15.2 Hz, 2H), 3.47 (s, 2H), 2.27 (s, 3H). 13C NMR (151 MHz, DMSO) δ 167.65, 162.25, 160.64, 153.49, 152.79, 146.61, 140.78, 137.52, 135.57, 134.83, 130.47, 130.42, 129.79, 129.27, 126.04, 125.10, 124.84, 117.70, 116.43, 114.97, 114.83, 113.32, 89.76, 44.72, 43.14, 21.07. EM-MS: m/z 499.2 (M+ 1). IR (cm-1, KBr): 1618 (CO), 3347 (NH). Anal. calcd. for C29H23ClFNO3: C, 69.87; H, 4.65; N, 5.62; found C,69.56; H, 4.56; N, 5.54.
Pharmacology
TNF-α activity
TNF-α assay was carried out as per previously reported method [15]. The TNF-α levels were detected using a ELISA kit (e-Bioscience, San Diego, CA.) as per the manufacturer’s protocol.
Anti-inflammatory activity
The anti-inflammatory activity was performed according to reported method [16]. The rats were divided into 9 groups of 5 animal each. The animals of positive control group orally received standard Indomethacin (20mg/kg) while the negative control group received 0.5% carboxymethyl cellulose (CMC) solution. Animals of experimental group were administered orally with synthesized test compounds (20mg/kg). After 60 min of administration, edema was induced by injecting 100 μL freshly prepared carrageenan solution (1.0% in 0.9% NaCl solution) in subplantar region of the right-hind paws. The right-hind paw volume was measured post carrageenan injection at interval of 3 h and 5 h by using digital plethysmometer. The anti-inflammatory activity (%) was calculated as follows:
Anti-inflammatory Activity (%) = [VC -Vt/VC] X 100
Where, Vt represents change in paw volume treated with test samples and VC represents change in paw volume in control group.
Analgesic activity
The peripheral analgesic activity was evaluated through writhing test using reported method [17]. Swiss albino mice (35–40 g) employed for this test which were divided into five groups and with five animals each. The Group I considered as control group orally administered with CMC suspension, Group II orally administered with standard drug indomethacin (20mg/kg) and test groups received synthesized compounds at oral dose of 20mg/kg. After 30 min of drug administration, 0.1% acetic acid was injected intraperitoneally. The muscular contractions were counted for a period of 10 min post injecting acetic acid. The total number of writhes recorded in 10 min expressed as writhing numbers.
Ulcerogenic activity
The ulcerogenic study was checked using previously reported method [18]. Compounds which demonstrated significant anti-inflammatory response were further tested for ulcerogenic effects. The rats in control group were orally administered 1% CMC suspension. Both standard and test groups were orally given a 60 mg dose of standard drug and test samples respectively. Animals were then sacrificed after 5 h of dosing.
Lipid peroxidation assay
Lipid peroxidation assay was carried out by the reported method [19]. The gastric mucosa was scraped with the help of two glass slides and weighed (100 mg) and homogenized in 1.8 ml of 1.15% ice cold KCl solution. Further, 1ml of suspension was taken from the supernatant, 0.5 ml of 30% trichloroacetic acid (TCA) followed by 0.5 ml of 0.8% thiobarbituric acid reagent added to it. The tubes were wrapped with aluminum foil and kept in a water bath for 30 min at 80°C with continuous shaking. After half hour, the tubes were kept in cold water for next 10 min. These were further centrifuged at 3000g for 15 min and the supernatant’s absorbance was read at 540 nm.