## 2 Materials and Methods
### Synthesis
\({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) (ppm): 2.55 (s, 3H, SCH\({}_{3}\)), 3.58 (s, 3H, OCH\({}_{3}\)), 3.67 (s, 6H, OCH\({}_{3}\)), 5.22 (s, 1H, CH), 6.57 (s, 2H), 7.77-7.85 (m, 2H, H9, H8), 7.93 (d, \(J\) = 8.53 Hz, 1H, H7), 8.03 (d, \(J\) = 8.78 Hz, 1H, H10), 9.49 (s, 1H, NH), 12.48 (s, 1H, NH). \({}^{13}\)C NMR \(\delta\) (ppm): 12.5 (SCH\({}_{3}\)), 34.5 (C5), 55.7 (OCH\({}_{3}\)), 59.6 (OCH\({}_{3}\)), 105.2 (Co), 125.4 (C7), 125.7 (C10), 133.0 (C8), 134.5 (C9), 135.6, 136.3 (C5a), 139.2, 140.3 (C1), 152.4 (C11a), 178.9 (C=O), 181.5 (C=O). MS: (70 eV) \(m/z\) (%) = 491 (48, M\({}^{+}\)), 460 (17), 325 (19), 324 (100), 276 (18). Anal. Calcd. for C\({}_{25}\)H\({}_{21}\)N\({}_{3}\)O\({}_{6}\)S C, 61.09; H, 4.31; N, 8.55; found C, 615-(4-fluorophenyl)-2-methylthio-5,12-dilhydrobenzo[g]pyrimidinido[4,5-b]quinoline-4,6,11(3H)-trione_ (**4f**). 70%. m.p. \(>\) 300 \({}^{\circ}\)C. IR (KBr, v cm\({}^{-1}\)), 3337 (NH st), 1656 (C=O st). \({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) (ppm): 2.56 (s, 3H, SCH\({}_{3}\)), 5.25 (s, 1H, H5), 7.03 (t, \(J\) = 8.79 Hz, 2H, H\({}_{0}\)), 7.34 (d, \(J\) = 7.03 Hz, 2H, H\({}_{0}\)), 7.79-7.83 (m, 2H, H8, H9), 7.90 (d, \(J\) = 6.78 Hz, 1H, H7), 8.03 (d, \(J\) = 7.28 Hz, 1H, H10), 9.64 (s, 1H, NH), 12.53 (s, 1H, NH). \({}^{13}\)C NMR \(\delta\) (ppm): 12.8 (SCH\({}_{3}\)), 35.7 (C5), 114.8 (Ca), 124.8 (C10), 128.6 (C7), 129.4 (Co), 129.5 (\(Cm\)), 131.1 (C8), 134.6 (C9), 141.2 (Ci), 145.5, 162.3, 178.6 (C=O). MS: (70 eV) \(m/z\) (%) = 419 (84, M\({}^{+}\)), 417, (25), 474 (50), 324 (100). Anal. Calcd. for C\({}_{22}\)H\({}_{14}\)FN\({}_{3}\)O\({}_{3}\)S C, 63.00; H, 3.36; N, 10.02; found C, 63.04; H, 3.34; N, 10.05. _5-(4-chlorophenylophenyl)-2-methylthio-5,12-dilhydrobenzo[g]pyrimidine[4,5-b]quinoline-4,6,11(3H)-trione_ (**4g**). 80%. m.p. \(>\) 300 \({}^{\circ}\)C. IR (KBr, v cm\({}^{-1}\)), 3367 (NH st), 2684 (CH\({}_{3}\) st), 1652, 1626 (C=O st). \({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) (ppm): 2.55 (s, 3H, SCH\({}_{3}\)), 5.23 (s, 1H, H5), 7.26 (d, \(J\) = 8.54 Hz, 2H, Ho), 7.32 (d, \(J\) = 8.54 Hz, 2H, H\({}_{0}\)), 7.79-7.82 (m, 2H, H8, H9), 7.90 (d, \(J\) = 7.03 Hz, 1H, H7), 8.03 (d, \(J\) = 7.03 Hz, 1H, H10), 9.66 (s, 1H, NH), 12.53 (s, 1H, NH). \({}^{13}\)C NMR \(\delta\) (ppm): 12.7 (SCH\({}_{3}\)), 34.3 (C5), 125.6 (C10), 125.9 (C7), 128.1 (Co), 129.7 (\(Cm\)), 130.4 (C6a), 131.8 (C10a), 133.3, 134.7 (C9), 139.4 (C5a), 143.9 (Ci), 178.5 (C4), 179.2 (C=O), 181.6 (C=O). MS: (70 eV) \(m/z\) (%) = 437 (6, M\({}^{+2}\)), 436 (5.7, M\({}^{+}\)), 435 (15, M\({}^{+}\)), 326 (6), 325 (18), 324 (100), 276 (13). Anal. Calcd. for C\({}_{22}\)H\({}_{14}\)CN\({}_{3}\)O\({}_{3}\)S C, 60.62; H, 3.24; N, 9.64; found C, 60.64; H, 3.22; N, 9.68. _5-(4-bromophenyl)-2-methylthio-5,12-dilhydrobenzo[g]pyrimidine[4,5-b]quinoline-4,6,11(3H)-trione_ (**4h**). 80%. m.p. \(>\) 300 \({}^{\circ}\)C. IR (KBr, v cm\({}^{-1}\)), 3369 (NH st), 1658 (C=O st). \({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) (ppm): 2.56 (s, 3H, SCH\({}_{3}\)), 5.33 (s, 1H, H5), 7.54 (d, \(J\) = 8.28 Hz, 2H, Ho), 7.58 (d, \(J\) = 8.28 Hz, 2H, H\({}_{0}\)), 7.77-7.82 (m, 2H, H8, H9), 7.89 (d, \(J\) = 7.27 Hz, H7), 8.03 (d, \(J\) = 7.03 Hz, H10), 9.72 (s, 1H, NH), 12.55 (s, 1H, NH). \({}^{13}\)C NMR \(\delta\) (ppm): 12.7 (SCH\({}_{3}\)), 35.0 (C5), 116.5 (C5a), 125.0, 125.6 (C10), 125.9 (C7), 127.8 (Co), 129.5 (Cm), 131.7 (C10a), 133.2 (C8), 134.7 (C9), 139.7 (Ci), 149.3 (C2), 162.2, 178.9 (C4), 179.0 (C=O), 181.5 (C=O). MS: (70 eV) \(m/z\) (%) = 469 (17), 467 (8), 325 (19), 324 (100), 276 (14). Anal. Calcd. for C\({}_{22}\)H\({}_{14}\)BrN\({}_{3}\)O\({}_{3}\)S C, 55.01; H, 2.94; N, 8.75; found C, 55.04; H, 2.98 N, 8.72. _3-methyl-2-(methylthio)-5-phenyl-5,12-dilhydrobenzo[g]pyrimidine[4,5-b]quinoline-4,6,11(3H)-trione_ (**4i**). Red solid. 81%. m.p. 277 \({}^{\circ}\)C. IR (KBr, v cm\({}^{-1}\)), 3227 (N-H st), 1647 (C=O, st), 1522 (C=C, st). \({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) (ppm): 2.62 (s, 3H, SCH\({}_{3}\)), 3.31 (s, 3H, NCH\({}_{3}\)), 5.24 (s, 1H.