calcd. for C15H10N2S: C, 71.97; H, 4.03; N, 11.19; S, 12.81. Found: C, 71.85; H, 3.97; N, 11.10; S, 12.77. 9-Fluoro-12(H)-quino[3,4-b][1,4]benzothiazine (4b) Yield 68 %; m.p.: 168–169 °C; 1H NMR (CD3OD, 500 MHz) δ (ppm): 6.64–6.68 (m, 1H, Harom), 6.70–6.75 (m, 1H, Harom), 6.87–6.91 (m, 1H, Harom), 7.44–7.49 (m, 1H, H-2), 7.56–7.61 (m, 1H, H-3), 7.73–7.76 (m, 1H, H-4), 8.01 (s, 1H, H-6), 8.05–8.09 (m, 1H, H-1); EI-MS m/z: 268 (M+, 100 %); Anal. calcd. for C15H9FN2S: C, 67.15; H, 3.38; N, 10.44; S, 11.95. Found: C, 67.09; H, 3.31; N, 10.40; S, 11.89. 9-Chloro-12(H)-quino[3,4-b][1,4]benzothiazine (4c) Yield 64 %; m.p.: 173–174 °C; 1H NMR (CD3OD, 500 MHz) δ (ppm): 6.88–6.91 (m, 2H, Harom), 7.02–7.05 (m, 1H, Harom), 7.55–7.60 (m, 1H, H-2), 7.68–7.73 (m, 1H, H-3), 7.78–7.82 (m, 1H, H-4), 8.12 (s, 1H, H-6), 8.17–8.20 Selleck CHIR 99021 (m, 1H, H-1); EI-MS m/z: 285 (M+, 100 %); Anal. calcd. for C15H9ClN2S: C, 63.27; H, 3.19; N, 9.84; S, 11.26. Found: C, 63.22; H, 3.15; N, 9.77; S, 11.23. 9-Bromo-12(H)-quino[3,4-b][1,4]benzothiazine (4d) Yield 54 %; m.p.: 96–98 °C; 1H NMR (CD3OD, 500 MHz) δ (ppm): 6.83–6.86 (m, 1H, Harom), 7.03–7.05 (m, 1H, Harom), 7.12–7.15 (m, 1H, Harom), 7.48–7.54 (m, 1H, H-2), 7.60–7.66 (m, 1H, H-3), 7.77–7.81 (m, 1H, H-4), 8.06 (s, 1H, Alvelestat in vitro H-6), 8.09–8.14 (m, 1H, H-1); EI-MS
m/z: 329 (M+, 100 %); Anal. calcd. for C15H9BrN2S: C, 54.73; H, 2.76; N, 8.51; S, 9.74. Found: C, 54.68; H, 2.73; N, 8.44; S, 9.71. 9-Methyl-12(H)-quino[3,4-b][1,4]benzothiazine (4e) Yield 83 %; m.p.: 202–203 °C; 1H NMR (CD3OD, 500 MHz) δ (ppm): 2.19 (s, 3H, CH3), 6.74–6.77 (m, 1H, Harom), 6.84–6.88 (m, 2H, Harom), 7.50–7.54 (m, 1H, H-2), Nintedanib (BIBF 1120) 7.61–7.65 (m, 1H, H-3), 7.78–7.81 (m, 1H, H-4), 8.09 (s, 1H, H-6), 8.14–8.18 (m, 1H, H-1); EI-MS m/z: 264 (M+, 100 %); Anal. calcd. for C16H12N2S:
C, 72.70; H, 4.58; N, 10.60; S, 12.13. Found: C, 72.61; H, 4.53; N, 10.53; S, 12.09. 11-Methyl-12(H)-quino[3,4-b][1,4]benzothiazine (4f) Yield 65 %; m.p.: 81–83 °C; 1H NMR (CD3OD, 500 MHz) δ (ppm): 2.36 (s, 3H, CH3), 6.77–6.84 (m, 2H, Harom), 6.90–6.95 (m, 1H, Harom), 7.50–7.55 (m, 1H, H-2), 7.59–7.64 (m, 1H, H-3), 7.70–7.82 (m, 1H, H-4), 7.98–8.03 (m, 1H, H-1), 8.13 (s, 1H, H-6); EI-MS m/z: 264 (M+, 100 %); Anal.