Vol. 31, No. 11 (2019)
Synthesis and Anticancer Evaluation of 2H-benzo[b][1,4]thiazin-3(4H)-one Based 1,2,3-Triazoles 2649
63 %; m.p.: 149-151 ºC; IR (KBr, cm-1): 3131 (CH-triazole),
1660 (C=O), 1589 (C=C), 1487, 1049, 664 (C-S); H NMR
Hz, 1H), 7.97 (d, J = 8.0 Hz, 1H), 7.83 (s, 1H, triazole-H), 7.75
(t, J = 8 Hz, 1H), 7.37 (t, J = 8 Hz, 1H), 7.31 (d, J = 4.0 Hz, 1H),
7.20 (t, J = 8 Hz, 1H), 7.11 (d, J = 8.0 Hz, 1H), 5.39 (s, 2H, N-
CH2), 4.25 (s, 2H, SO2-CH2), 2.35 (s, 3H, Ar-CH3), 1.96 (s,
3H, Ar-CH3); 13C NMR (100 MHz, CDCl3, δ in ppm): 160.98,
138.88, 135.39, 132.51, 131.52, 128.25, 126.15, 124.88, 124.37,
123.81, 120.01, 117.80, 57.00, 41.43, 20.36, 14.26; MS (ESI)
m/z: 383 [M+H]; Anal. calcd. (found) % for C19H18N4O3S: C,
59.67 (59.71); H, 4.74 (4.69); N, 14.65 (14.70).
1
(400 MHz, CDCl3, δinppm): 8.09 (s, 1H, triazole-H ), 7.83 (d,
J = 8.0 Hz, 1H), 7.66-7.60 (m, 4H), 7.37-7.27 (m, 2H), 7.05 (t,
J = 8.0 Hz, 1H), 5.26 (s, 2H, N-CH2), 3.42 (s, 2H, S-CH2); 13C
NMR (100 MHz, CDCl3, δ in ppm): 163.88, 139.84, 135.90,
132.91, 128.23, 127.76, 124.04, 123.29, 122.51, 122.04, 121.98,
121.88, 118.72, 40.63, 30.66; MS (ESI) m/z: 403 [M+2H];
Anal. calcd. (found) % for C17H13N4OSBr: C, 50.88 (50.91);
H, 3.27 (3.23); N, 13.96 (14.01).
4-((1-(3,5-Dichlorophenyl)-1H-1,2,3-triazol-4-yl)-
methyl)-2H-benzo[b][1,4]thiazin-3(4H)-one-1,1-dioxide
(5c): Pale yellow solid, yield: 84 %; m.p.: 222-224 ºC; IR (KBr,
cm-1): 3158 (CH-triazole), 1677 (C=O), 1592 (C=C), 1472, &
1128 (SO2); 1H NMR (400 MHz, CDCl3, δinppm): 8.12 (s, 1H,
triazole-H), 8.07 (d, J = 8 Hz, 1H), 7.98 (d, J = 8 Hz, 1H), 7.74
(t, J = 8 Hz, 1H), 7.67 (s, 2H), 7.43 (s, 1H), 7.39 (m, 1H), 5.36 (s, 2H,
N-CH2), 4.26 (s, 2H, SO2-CH2); 13C NMR (100 MHz, CDCl3,
δ in ppm): 160.50, 144.17, 138.70, 137.05, 135.25, 127.77,
127.22, 126.74, 123.06, 122.28, 121.05, 117.79, 117.57, 57.31,
41.01; MS (ESI) m/z: 424 [M+H]. Anal. calcd. (found) % for
C17H12N4O3SCl2: C, 48.24 (48.27); H, 2.86 (2.90); N, 13.24 (13.29).
4-((1-(3,5-Dimethylphenyl)-1H-1,2,3-triazol-4-yl)-
methyl)-2H-benzo[b][1,4]thiazin-3(4H)-one-1,1-dioxide
(5d): White solid, yield: 65 %; m.p.: 184-186 ºC; IR (KBr, cm-1):
3129 (CH-triazole), 1670 (C=O), 1585 (C=C), 1488 & 1137 (SO2);
1H NMR (400 MHz, CDCl3, δinppm): 8.13 (t, J = 8.0 Hz, 1H),
8.09 (s, 1H, triazole-H ), 7.96 (dd, J = 4.0, 4.0 Hz, 1H), 7.74
(t, J = 8.0 Hz, 1H), 7.36-7.25 (m, 3H), 7.06 (s, 1H), 5.35 (s, 2H, N-
CH2), 4.26 (s, 2H ,SO2-CH2), 2.38 (s, 6H, Ar-CH3); 13C NMR
(100 MHz, CDCl3, δ in ppm): 160.34, 144.15, 141.69, 138.77,
136.70, 132.05, 129.78, 126.72, 123.00, 122.26, 121.05, 119.73,
117.39, 117.66, 56.97, 41.58, 21.13; MS (ESI) m/z: 383 [M+H];
Anal. calcd. (found) % for C19H18N4O3S: C, 59.67 (59.63); H,
4.74 (4.71); N, 14.65 (14.69).
4-((1-(o-Tolyl)-1H-1,2,3-triazol-4-yl)methyl)-2H-benzo-
[b][1,4] thiazin-3(4H)-one-1,1-dioxide (5e): White solid; yield:
69 %, m.p.: 169-171 ºC; IR (KBr, cm-1): 3157 (CH-triazole),
1680 (C=O), 1594 (C=C), 1475 & 1137 (SO2); 1H NMR (400
MHz, CDCl3, δ in ppm): 8.18-8.13 (m, 1H), 8.00 -7.92 (m, 1H),
7.88 (s, 1H, triazole-H ), 7.75 (t, J = 8.0 Hz, 1H), 7.43-7.27 (m,
5H), 5.39 (s, 2H, N-CH2), 4.25 (s, 2H, SO2-CH2), 2.17 (s, 3H, Ar-
CH3); 13C NMR (100 MHz, CDCl3, δ in ppm): 160.38, 143.93,
141.38, 138.30, 136.22, 135.33, 133.45, 131.55, 129.99, 128.37,
126.87, 125.81, 124.84, 124.33, 119.98, 57.03, 41.33, 18.41;
ESI-MS m/z: 369 [M+H];Anal. calcd. (found) % for C18H16N4O3S:
C, 58.68 (58.75); H, 4.38 (4.33); N, 15.21 (15.29).
4-((1-(3-Chlorophenyl)-1H-1,2,3-triazol-4-yl)methyl)-
2H-benzo[b][1,4]thiazin-3(4H)-one (4h): Pale yellow solid,
yield: 64 %; m.p.: 148-150 ºC; IR (KBr, cm-1): 3151 (CH-triazole),
1658 (C=O), 1593 (C=C), 1496, 1043, 667 (C-S); 1H NMR (400
MHz, CDCl3, δ in ppm): 8.10 (s, 1H, triazole-H), 7.83-7.78
(m, 2H), 7.65-7.62 (m, 1H), 7.47-7.27 (m, 4H) 7.05 (t, J = 8.0
Hz, 1H), 5.27 (s, 2H, N-CH2), 3.43 (s, 2H, S-CH2); 13C NMR
(100 MHz, CDCl3, δ inppm): 163.37, 145.79, 143.33, 137.99,
135.17, 128.00, 127.78, 125.38, 125.28, 122.09, 119.34, 118.55,
117.35, 114.85, 41.07, 30.24; MS (ESI) m/z: 357 [M+H];Anal.
calcd. (found) % for C17H13N4OSCl: C, 57.22 (57.27); H, 3.67
(3.73); N, 15.70 (15.76).
4-((1-(3-(Trifluoromethyl)phenyl)-1H-1,2,3-triazol-4-
yl)methyl)-2H-benzo[b][1,4]thiazin-3(4H)-one (4i): Yellow
solid, yield: 53 %; m.p.: 130-132 ºC; IR (KBr, cm-1): 3142
(CH-triazole), 1659 (C=O), 1594 (C=C), 1490, 1048, 659 (C-S);
1H NMR (400 MHz, CDCl3, δinppm): 7.89 (s, 1H, triazole-H),
7.86 (d, J = 8.0 Hz, 1H), 7.73 (s, 1H), 7.38-7.30 (m, 3H), 7.28-
7.14 (m, 1H), 7.11-7.02 (m, 2H), 5.30 (s, 2H, N-CH2), 3.42 (s, 2H,
S-CH2); ESI-MS m/z: 391 [M+H]; Anal. calcd. (found) % for
C18H13N4OSF3:C, 55.38 (55.33); H, 3.36 (3.40); N, 14.35 (14.39).
4-((1-(2-Fluorophenyl)-1H-1,2,3-triazol-4-yl)methyl)-
2H-benzo[b][1,4] thiazin-3(4H)-one (4j): Pale red solid, yield:
67 %; m.p.: 147-149 ºC; IR (KBr, cm-1): 3149 (CH-triazole),
1662 (C=O), 1584 (C=C), 1490, 1037, 662 (C-S); 1H NMR (400
MHz, CDCl3, δ in ppm): 8.10 (s, 1H, triazole-H), 7.93-7.87
(m, 2H), 7.82-7.74 (m, 2H), 7.65-7.61 (m, 1H), 7.49-7.28 (m,
2H), 7.06-7.02 (m, 1H), 5.28 (s, 2H, N-CH2), 3.43 (s, 2H, S-CH2);
MS (ESI) m/z:341[M+H];Anal. calcd. (found)%forC17H13N4OSF:
C, 59.99; H, 3.85; N, 16.46; found: C, 60.04; H, 3.92; N, 16.51.
4-((1-(4-Methoxyphenyl)-1H-1,2,3-triazol-4-yl)methyl)-
2H-benzo[b][1,4]thiazin-3(4H)-one-1,1-dioxide (5a): White
solid, yield: 79 %; m.p.: 206-208 ºC; IR (KBr, cm-1): 3133 (CH-
triazole), 1680 (C=O), 1588 (C=C), 1480, & 1132 (SO2); 1H NMR
(400 MHz, CDCl3, δinppm): 8.14 (m, 1H), 8.03 (s, 1H, triazole-
H), 7.99- 7.94 (m, 1H), 7.73 (t, J = 8 Hz, 1H), 7.61-7.57 (m,
2H), 7.39-7.33 (m, 1H), 7.04-6.98 (m, 2H), 5.36 (s, 2H, N-CH2),
4.35 (s, 2H, SO2-CH2), 3.86 (s, 3H, O-CH3); 13C NMR (100 MHz,
CDCl3, δinppm): 160.73, 159.35, 145.70, 143.05, 135.92, 133.03,
129.86, 127.96, 125.24, 121.62, 119.27, 117.45, 114.75, 57.51,
55.77, 41.25; MS (ESI) m/z: 385 [M+H]. Anal. calcd. (found) %
for C18H16N4O4S: C, 56.24 (56.18); H, 4.20 (4.25); N, 14.57
(14.63).
4-((1-Phenyl-1H-1,2,3-triazol-4-yl)methyl)-2H-benzo-
[b][1,4]thiazin-3(4H)-one-1,1-dioxide (5f): White solid; yield:
67 %, m.p.: 144-146 ºC; IR (KBr, cm-1): 3131 (CH-triazole), 1674
(C=O), 1587 (C=C), 1485 & 1138 (SO2); 1H NMR (400 MHz,
CDCl3, δ in ppm): 8.15 (s, 1H), 8.12 (s, 1H, triazole-H), 8.00-
7.92 (m, 1H), 7.78-7.67 (m, 3H), 7.57-7.49 (m, 2H), 7.47-7.40
(m, 1H), 7.38-7.30 (m, 1H), 5.37 (s, 2H, N-CH2), 4.26 (s, 2H,
SO2-CH2); 13C NMR (100 MHz, CDCl3, δ in ppm): 160.34,
143.08, 139.45, 137.57, 136.49, 130.12, 126.72, 124.88, 123.02,
122.14, 120.29, 117.80, 114.26, 57.06, 41.12; MS (ESI) m/z:
355 [M+H]; Anal. calcd. (found) % for C17H14N4O3S: C, 57.62
(57.67); H, 3.98 (3.93); N, 15.81 (15.74).
4-((1-(2,3-Dimethylphenyl)-1H-1,2,3-triazol-4-yl)-
methyl)-2H-benzo[b][1,4]thiazin-3(4H)-one-1,1-dioxide
(5b): White solid, yield: 73 %; m.p.: 179-181 ºC; IR (KBr, cm-1):
3140 (CH-triazole), 1672 (C=O), 1591 (C=C), 1475 & 1133
(SO2); 1H NMR (400 MHz, CDCl3, δ in ppm): 8.16 (d, J = 8.0