2.5. General Procedure for the Synthesis of N'-[benzoyl] N'-8-methyl-4-oxo-1,4-dihydroquinoline-3-carbohydrazide Series (8a-g)
At ambient temperature, a mixture of compound 7 (0.30 g, 1.38 mmol), substituted benzoyl chloride (1.38 mmol), and Na2CO3 (0.4 mmol) was prepared in DMF and stirred for 17 hours. After completion of the reaction, the mixture was slowly poured over crushed ice. The solid was filtered, washed with water, and then recrystallized from ethanol to obtain the final compound.
2.5.1. N'-benzoyl- 8-methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbohydrazide (8a)
Yield: 50%; white powder; mp: 274 - 275ºC; IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1630 (carbonyl), 3276 (N-H) cm-1; LCMS (ESI): m/z 322.10 [M+H+], 344.10 [M+Na+]; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.53 (s, 3H, CH3), 7.36-7.39 (t, 1H, benzoyl H4' J = 7.7 Hz), 7.46-7.49 (t, 2H, benzoyl H3' & H5' , J = 7.4 Hz), 7.54-7.56 (t, 1H, H6, J = 7.3 Hz), 7.61 - 7.63 (d, 1H, H7, J = 7.0 Hz), 7.88 - 7.90 (d, 2H, benzoyl H2' & H6' J = 7.3 Hz), 8.14 - 8.15 (d, 1H, H5, J = 7.9 Hz), 8.61 (s, 1H, H2), 10.76 (s, 1H, NH), 11.69 (s, 1H, NH), 12.11 (br s, 1H, enolic OH). 13C NMR (DMSO-d6, 126 MHz): δ 17.53, 110.32, 123.88, 125.35, 126.64, 127.90, 128.02, 128.93, 132.28, 132.88, 134.20, 138.12, 143.91, 164.01, 165.29, 176.50; Anal. Calcd. for C18H15N3O3: C, 67.28; H, 4.71; N, 13.08. Found: C, 67.37; H, 4.91; N, 13.22.
2.5.2. N'-(4-fluorobenzoyl)- 8-methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbohydrazide (8b)
Yield: 44.9%; mp: 291 - 293ºC; IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1600,1623 (carbonyl), 3247 (N-H) cm-1; MS (ESI): m/z 338 [M-H]-; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.58 (s, 3H, CH3), 7.35 - 7.38 (t, 2H, 4-fluorobenzoyl H3' & H5', J = 8.8 Hz), 7.40 - 7.42 (t, 1H, H6, J = 7.8 Hz), 7.65 - 7.67 (d, 1H, H7, J = 7.1 Hz), 7.94 - 8.02 (dd, 2H, 4-fluorobenzoyl H2' & H6'), 8.17-8.18 (d, 1H, H5, J = 8.0 Hz), 8.65 (s, 1H, H2), 10.86 (s, 1H, NH), 11.75 (s, 1H, NH), 12.15 (br s, 1H, enolic OH). 13C NMR (DMSO-d6, 126 MHz): δ 17.52, 110.26, 115.95, 123.87, 125.35, 126.62, 127.91, 129.36, 130.74, 134.20, 138.12, 143.92, 163.41, 164.12, 165.89, 176.49. Anal. Calcd. for C18H14FN3O3: C, 63.71; H, 4.16; N, 12.38. Found: C, 63.56; H, 4.27; N, 12.64.
2.5.3. N'-(3-fluorobenzoyl)- 8-methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbohydrazide (8c)
Yield: 75%; white powder; mp: 274.4 - 276.9°C; IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1620,1663 (carbonyl), 3280 (N-H) cm-1; LCMS (ESI): m/z 337.7 [M-H]-; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.50 (s, 3H, CH3), 7.31 - 7.37 (dd, 1H, 3-fluorobenzoyl H4', J = 7.6 Hz), 7.39 - 7.41 (t, 1H, H6), 7.55-7.57 (m, 1H, , 3-fluorobenzoyl H5'), 7.66 - 7.68 (d, 1H, , 3-fluorobenzoyl H2', J = 9.5 Hz), 7.73 - 7.75 (d, 1H, H7, J = 7.8 Hz), 8.06 - 8.08 (d, 1H, 3-fluorobenzoyl H6', J = 7.9 Hz), 8.12 - 8.13 (d, 1H, H5, J = 7.9 Hz), 8.60 (s, 1H, H2), 10.64 (s, 1H, NH), 11.72 (s, 1H, NH), 12.2 (br s, 1H, enolic OH). 13C NMR (DMSO-d6, 126 MHz): δ 17.52, 110.20, 114.82, 119.24, 123.86, 124.23, 125.37, 126.62, 127.93, 131.20, 134.21, 135.15, 138.13, 143.95, 161.16, 163.59, 165.96, 176.48. Anal. Calcd. for C18H14FN3O3: C, 63.71; H, 4.16; N, 12.38. Found: C, 63.49; H, 4.25; N, 12.54.
2.5.4. N'-(4-chlorobenzoyl)- 8-methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbohydrazide (8d)
Yield: 39%; white powder; mp: 304 - 305.2ºC; IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1637,1665 (carbonyl), 3295 (N-H) cm-1; LCMS (ESI): m/z 354 [M-H]-; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.58 (s, 3H, CH3), 7.42-7.45 (t, 1H, H6, J =7.5 Hz), 7.60 - 7.62 (d, 2H, 4-chlorobenzoyl H3' & H5', J = 8.5 Hz), 7.67 - 7.68 (d, 1H, H7, J = 7.0 Hz), 7.94 - 7.96 (d, 2H, 4-chlorobenzoyl H2' & H6', J = 8.5 Hz), 8.18 - 8.20 (d, 1H, H5, J = 7.9 Hz), 8.65 (s, 1H, H2), 10.93 (s, 1H, NH), 11.77 (s,1H, NH), 11.80 (br s, 1H, enolic OH). 13C NMR (DMSO-d6, 126 MHz): δ 17.52, 110.24, 123.87, 125.33, 126.61, 127.88, 129.04, 129.95, 131.61, 134.19, 137.12, 138.11, 143.91, 163.93, 164.24, 176.48. Anal. Calcd. for C18H14ClN3O3: C, 60.77; H, 3.97; N, 11.81. Found: C, 60.95; H, 3.75; N, 11.61.
2.5.5. 8-Methyl-N'-(4-methylbenzoyl)- 4-oxo- 1,4-dihydroquinoline- 3-carbohydrazide (8e)
Yield: 80%; white powder; mp: 260 - 261.4°C; IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic),1630,1673 (carbonyl), 3298 (N-H) cm-1; LCMS (ESI): m/z 336.10 [M+H+]; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.39 (s, 3H, CH3), 2.58 (s, 3H, CH3), 7.32 - 7.33 (d, 2H, 4-methylbenzoyl H3' & H5', J = 7.9 Hz), 7.41 - 7.44 (t, 1H, H6, J = 7.6 Hz), 7.66 - 7.68 (d, 1H, H7, J = 7.1 Hz ), 7.83 - 7.84 (d, 2H, 4-methylbenzoyl H2' & H6', J = 7.9 Hz), 8.17 - 8.19 (d, 1H, H5, J = 8.0 Hz), 8.65 (s, 1H, H2), 10.72 (s, 1H, NH), 11.70 (s, 1H, NH), 12.15 (br s, 1H, enolic OH). 13C NMR (DMSO-d6, 126 MHz): δ 17.52, 21.50, 110.33, 123.86, 125.31, 126.62, 127.89, 128.03, 129.44, 130.06, 134.16, 138.11, 142.26, 143.88, 164.01, 165.19, 176.48. Anal. Calcd. for C19H17N3O3: C, 68.05; H, 5.11; N, 12.53. Found: C, 68.25; H, 5.26; N, 12.72.
2.5.6. 8-Methyl-N'-(3-methylbenzoyl)- 4-oxo- 1,4-dihydroquinoline- 3-carbohydrazide (8f)
Yield: 50%; white powder; mp: 292 - 293.7ºC; IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1650,1670 (carbonyl), 3277,3396 (N-H) cm-1; LCMS (ESI): m/z 334 [M-H]-; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.34 (s, 3H, CH3), 2.53 (s, 3H, CH3), 7.34 - 7.40 (m, 3H, H6, 3-methylbenzoyl H4' & H5'), 7.61 - 7.63 (d, 1H, H7, J = 7.1 Hz), 7.67 - 7.70 (m, 2H, 3-methylbenzoyl H2' & H6'), 8.13 - 8.15 (d, 1H, H5, J = 8.0 Hz), 8.60 (s, 1H, H2), 10.69 (s, 1H, NH), 11.68 (s, 1H, NH), 12.12 (br s, 1H, enolic OH). 13C NMR (DMSO-d6, 126 MHz): δ 17.53, 21.41, 110.33, 123.89, 125.12, 125.38, 126.65, 127.92, 128.57, 128.81, 132.86, 134.22, 138.14, 138.22, 143.92, 163.93, 165.37, 176.51. Anal. Calcd. for C19H17N3O3: C, 68.05; H, 5.11; N, 12.53. Found: C, 68.25; H, 5.29; N, 12.74.
2.5.7. N'-(4-methoxybenzoyl)- 8-methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbohydrazide (8g)
Yield: 70%; white powder; mp: 274ºC (decomposed); IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1678 (carbonyl), 3276 (N-H) cm-1; LCMS (ESI): m/z 349.70 [M-H]-; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.59 (s, 3H, CH3), 3.84 (s, 3H, OCH3), 7.05 - 7.06 (d, 2H, 4-methoxybenzoyl H3' & H5', J = 8.8 Hz), 7.42 - 7.45 (t, 1H, H6, J = 7.5 Hz), 7.67 - 7.68 (d, 1H, H7, J = 7.1 Hz), 7.91 - 7.93 (d, 2H, 4-methoxybenzoyl H2' & H6', J = 8.7 Hz), 8.18 - 8.20 (d, 1H, H5, J = 7.9 Hz), 8.65 (s, 1H, H2), 10.65 (s, 1H, NH), 11.68 (s, 1H, NH), 12.16 (br s, 1H, enolic OH). 13C NMR (DMSO-d6, 126 MHz): δ 17.52, 55.85, 110.38, 114.14, 123.88, 124.98, 125.33, 126.64, 127.89, 129.90, 134.18, 138.12, 143.88, 162.45, 164.04, 164.81, 176.50. Anal. Calcd. for C19H17N3O4: C, 64.95; H, 4.88; N, 11.96. Found: C, 64.75; H, 5.02; N, 11.81.
2.6. General Procedure for the Synthesis of N-(phenyl)- 2-(8-methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbonyl) hydrazine- 1-carboxamide Series (9a-c)
Compound 7 (0.22 g, 0.1 mmol) was dissolved in dry DMF (4 mL). Then, isocyanate derivatives (0.1 mmol) were progressively added to the mixture. The reaction solution was stirred for 24 hours at room temperature. Thin-layer chromatography was used to monitor and control the product. Water and ice were poured into the reaction to form a precipitate, which was then filtered through a Buchner funnel and thoroughly rinsed with plenty of water. The precipitate was crystallized using 96% ethanol solution.
2.6.1. 2-(8-Methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbonyl)- N-phenylhydrazine- 1-carboxamide (9a)
Yield: 73%; white powder; mp: 310.9°C (decomposed); IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1641,1676 (C=O), 2589 - 3500 (OH), 3338, 3462 (NH) cm-1; LCMS (ESI): m/z 337.0 [M+H+]; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.57 (s, 3H, CH3), 6.94 - 6.98 (t, 1H, N-phenyl H4' , J = 8.0 Hz), 7.24 - 7.28 (t, 2H, N-phenyl H3' & H5', J = 8.0 Hz), 7.40 - 7.44 (t, 1H, H6, J = 8.0 Hz), 7.47 (d, 2H, N-phenyl H2' & H6', J = 8.0 Hz) 7.65 (d, 1H, H7, J = 4.0 Hz), 8.17 (d, 1H, H5, J = 8.0 Hz), 8.45 (br s, 1H, NH), 8.61 (s, 1H, H2), 8.92 (s, 1H, NH), 11.41 (br s, 1H, NH), 12.14 (br s, 1H, enolic OH); 13C NMR (DMSO-d6, 126 MHz): δ 17.51, 110.45, 118.79, 122.32, 123.88, 125.30, 126.69, 127.86, 129.14, 134.16, 138.12, 140.12, 143.78, 155.34, 164.45, 176.44; Anal. Calcd. for C18H16N4O3: C, 64.28; H, 4.79; N, 16.66. Found: C, 64.42; H, 4.66; N, 16.85.
2.6.2. N-benzyl- 2-(8-methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbonyl) hydrazine- 1-carboxamide (9b)
Yield: 70%; white powder; mp: 280.1°C (decomposed); IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1653 (C=O), 2783 - 3429 (OH), 3310 (NH) cm-1; LCMS (ESI): m/z 351 [M+H+] ,372.9 [M+Na+]; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.56 (s, 3H, CH3), 4.25 (d, 2H, -CH2, J = 4.0 Hz), 7.07 (br s, 1H, NH), 7.21 - 7.24 (t, 1H, N-benzyl H4', J = 8.0 Hz), 7.27 - 7.34 (m, 4H, N-benzyl H2', H3', H5' & H6'), 7.38-7.42 (t, 1H, H6, J = 8.0 Hz),7.65 (d, 1H, H7, J = 8.0 Hz), 8.15 (d, 1H, H5, J = 8.0 Hz), 8.22 (br s, 1H, NH), 8.61 (s, 1H, H2), 11.26 (br s, 1H, NH), 12.12 (br s,1H, enolic OH); 13C NMR (DMSO-d6, 126 MHz): δ 17.51, 110.65, 123.88, 125.25, 126.69, 127.02, 127.44, 127.81, 128.62, 134.12, 138.09, 140.99, 143.73, 158.38, 164.72, 176.43; Anal. Calcd. for C19H18N4O3: C, 65.13; H, 5.18; N, 15.99. Found: C, 65.25; H, 5.33; N, 15.78.
2.6.3. N-(3,4-dichlorophenyl)- 2-(8-methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbonyl) hydrazine- 1-carboxamide (9c)
Yield: 62%; white powder; mp: 292.4°C (decomposed); IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1648, 1686 (C=O), 2587 - 3500 (OH), 3335, 3488 (NH) cm-1; LCMS (ESI): m/z 405.0 [M+H+]; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.57 (s, 3H, CH3), 7.40 - 7.44 (t, 2H, H6, J = 8.0 Hz), 7.49 - 7.50 (d, 1H, 3,4-dichlorophenyl H6', J = 8.0 Hz), 7.65 - 7.67 (d, 1H, H7, J = 8.0 Hz), 7.87 (d, 1H, 3,4-dichlorophenyl H5', J = 8.0 Hz), 8.17 (d, 1H, H5, J = 8.0 Hz), 8.61 (s, 1H, H2), 8.64 (s, 1H, 3,4-dichlorophenyl H2'), 9.24 (s,1H, NH), 11. 38 (br s, 1H, NH), 12.16 (br s, 1H, enolic OH); 13C NMR (DMSO-d6, 126 MHz): δ 17.52, 110.43, 118.97, 119.99, 123.57, 123.88, 125.36, 126.70, 127.89, 130.92, 131.31, 134.21, 138.12, 140.49, 143.86, 176.46; Anal. Calcd. for C18H14Cl2N4O3: C, 53.35; H, 3.48; N, 13.83. Found: C, 53.52; H, 3.59; N, 13.99.
2.7. General Procedure for the Synthesis of 2-(8-dimethyl- 4-oxo- 1,4-dihydroquinoline- 3-carbonyl)- N-phenylhydrazine- 1-carbothioamide (10a-f)
Compound 7 (0.22 g, 0.1 mmol) was dissolved in dry DMF (4 mL). Next, isothiocyanate derivatives (0.1 mmol) were progressively added to the mixture. The reaction solution was stirred for 4 hours at room temperature. Thin-layer chromatography was used to monitor and control the product. Water and ice were poured into the reaction to form a precipitate, which was then filtered through a Buchner funnel and thoroughly rinsed with plenty of water. The precipitate was crystallized using 96% ethanol solution.
2.7.1. 2-(8-Methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbonyl)- N-phenylhydrazine- 1-carbothioamide (10a)
Yield: 80%; white powder; mp: 237.6°C (decomposed); IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1646,1662 (C=O), 2765 - 3392 (OH), 3224, 3324 (NH) cm-1; LCMS (ESI): m/z 374.8 [M+Na+], 353.0 [M+H]+; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.58 (s, 3H,CH3), 7.12 - 7.16 (t, 1H, N-phenyl H4' , J = 8.0 Hz), 7.31 - 7.35 (t, 2H, N-phenyl H3' & H5', J = 8.0 Hz), 7.40 - 7.44 (t, 1H, H6, J = 8.0 Hz), 7.53 (m, 2H, N-phenyl H2' & H6'), 7.66 (d, 1H, H7, J = 8.0 Hz), 8.18 (d, 1H, H5, J = 8.0 Hz), 8.62 (s, 1H, H2), 9.87 (br s, 2H, NH), 12.16 (br s, 1H, enolic OH), 13C NMR (DMSO-d6, 126 MHz): δ 17.52, 123.89, 125.36, 126.64, 127.87, 128.72, 134.22, 138.10, 139.73, 143.71, 176.33; Anal. Calcd. for C18H16N4O2S: C, 61.35; H, 4.58; N, 15.90. Found: C, 61.42; H, 4.80; N, 15.70.
2.7.2. 2-(8-Methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbonyl)- N-(o-tolyl) hydrazine- 1-carbothioamide (10b)
Yield: 81%; white powder; mp: 237.1°C (decomposed); IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1648, 1670 (C=O), 2878 - 3400 (OH), 3130, 3290 (NH) cm-1; LCMS (ESI): m/z 367.0 [M+H+]; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.21 (s, 3H, CH3), 2.57 (s, 3H, 8-CH3), 7.13 - 7.22 (m, 4H, N-o-tolyl H3', H4', H5' & H6'),7.40 - 7.44 (t, 1H, H6, J = 8.0 Hz), 7.66 (d, 1H, H7, J = 8.0 Hz), 8.17 (d, 1H, H5, J = 8.0 Hz), 8.62 (s, 1H, H2), 9.53 (br s, 1H, NH), 9.72 (br s, 1H, NH), 11. 49 (br s, 1H, NH), 12.15 (br s, 1H, enolic OH), 13C NMR (DMSO-d6, 126 MHz): δ 17.53, 18.18, 123.89, 125.33, 126.64, 126.88, 127.85, 130.57, 134.20, 138.09, 143.67, 158.38, 164.72, 176.43; Anal. Calcd. for C19H18N4O2S: C, 62.28; H, 4.95; N, 15.29. Found: C, 62.36; H, 4.85; N, 15.39.
2.7.3. 2-(8-Methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbonyl)-N-(m-tolyl) hydrazine- 1-carbothioamide (10c)
Yield: 75.6%; white powder; mp: 212.6°C; IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1668 (C=O), 2759 - 3500 (OH), 3230, 3330 (NH) cm-1; LCMS (ESI): m/z 367 [M+H+]; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.29 (s, 3H, CH3), 2.58 (s, 3H, 8-CH3), 6.95 (d, 1H, m-tolyl H4', J= 8.0 Hz), 7.19 - 7.23 (t, 1H, m-tolyl H5', J = 8.0 Hz), 7.34 (m, 2H, m-tolyl H2' & H6'), 7.40 - 7.44 (t, 1H, H6, J = 8.0 Hz), 7.66 (d, 1H, H7, J = 8.0 Hz), 8.18 (d, 1H, H5, J = 8.0 Hz), 8.62 (s, 1H, H2), 9.80 (br s, 2H, NH), 12.16 (d, 1H, enolic OH), 13C NMR (DMSO-d6, 126 MHz): δ 17.53, 21.47, 123.89, 125.36, 126.64, 127.87, 134.22, 138.09, 139.59, 143.70, 176.32; Anal. Calcd. for C19H18N4O2S: C, 62.28; H, 4.95; N, 15.29. Found: C, 62.39; H, 5.12; N, 15.39.
2.7.4. 2-(8-Methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbonyl)- N-(p-tolyl) hydrazine- 1-carbothioamide (10d)
Yield: 85.6%; white powder; mp: 232.4°C (decomposed); IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1615,1639 (C=O), 2757 - 3379 (OH), 3210, 3250 (NH) cm-1; LCMS (ESI): m/z 367 [M+H+]; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.28 (s, 3H, CH3), 2.57 (s, 3H, 8-CH3), 7.13 (d, 2H, p-tolyl H3' & H5', J = 8.0 Hz), 7.38 - 7.44 (m, 3H, H6 and p-tolyl H2' & H6'),7.66 (d, 1H, H7, J = 8.0 Hz), 8.17 (d, 1H, H5, J = 8.0 Hz), 8.61 (s, 1H, H2), 9.79 (br s, 2H, NH), 12.15 (br s, 1H, enolic OH), 13C NMR (DMSO-d6, 126 MHz): δ 17.52, 21.00, 123.89, 125.35, 126.64, 127.86, 129.17, 134.21, 137.11, 138.09, 143.69, 176.33; Anal. Calcd. for C19H18N4O2S: C, 62.28; H, 4.95; N, 15.29. Found: C, 62.35; H, 4.73; N, 15.09.
2.7.5. 2-(8-Methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbonyl)- N-(4-fluorophenyl) hydrazine- 1-carbothioamide (10e)
Yield: 81%; white powder; mp: 239.7°C (decomposed); IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1647, 1662 (C=O), 2789 - 3500 (OH), 3218 (NH) cm-1; LCMS (ESI): m/z 370.8 [M+H+]; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.58 (s, 3H, CH3), 7.14 - 7.19 (t, 2H, 4-fluorophenyl H3' & H5', JH,F = 12.0 Hz), 7.40 - 7.44 (t, 1H, H6, J = 8.0 Hz), 7.49 (m, 2H, 4-fluorophenyl H2' & H6'), 7.66 (d, 1H, H7, J = 8.0 Hz), 8.17 (d, 1H, H5, J = 8.0 Hz), 8.62 (s, 1H, H2), 9.85 (br s, 2H, NH), 12.17 (br s, 1H, enolic OH), 13C NMR (DMSO-d6, 126 MHz): δ 17.53, 115.36, 123.89, 125.39, 126.64, 127.89, 134.24, 136.05, 138.10, 143.75, 176.35. Anal. Calcd. for C18H15FN4O2S: C, 58.37; H, 4.08; N, 15.13. Found: C, 58.55; H, 4.22; N, 15.28.
2.7.6. N-(4-methoxyphenyl)- 2-(8-methyl- 4-oxo- 1,4-dihydroquinoline- 3-carbonyl) hydrazine- 1-carbothioamide (10f)
Yield: 70.2%; white powder; mp: 230.7 - 233.3°C (decomposed); IR (KBr, spectroscopic grade): 1400 - 1600 (aromatic), 1648 (C=O), 2795 - 3395 (OH), 3259 (NH) cm-1; LCMS (ESI): m/z 383.1 [M+H+]; 1H NMR (500 MHz, DMSO-d6): δ ppm 2.57 (s, 3H, CH3), 3.74 (s, 3H, OCH3), 6.90 (d, 2H, 4-methoxyphenyl H3' & H5', J = 8.0 Hz), 7.35 (d, 2H, 4-methoxyphenyl H2' & H6', J = 8.0 Hz), 7.40-7.44 (t, 1H, H6, J = 8.0 Hz), 7.66 (d, 1H, H7, J = 8.0 Hz), 8.17 (d, 1H, H5, J = 8.0 Hz), 8.61 (s, 1H, H2), 9.72 (br s, 2H, NH), 12.14 (br s, 1H, enolic OH); Anal. Calcd. for C19H18N4O3S: C, 59.67; H, 4.74; N, 14.65. Found: C, 59.53; H, 4.66; N, 14.38.