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V. Mathew et al.
Arch. Pharm. Chem. Life Sci. 2009, 342, 210–222
64.84; H, 4.53; N, 21.01; S, 9.62. Found: C, 64.73; H, 4.51; N, 20.85;
S, 9.54. Rf value = 0.46.
3-(2-(N-Methylamino)phenyl)-6-[5-chloro-2-furanyl]-5,6-
dihydro-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole 12b
Yield: 32%; m.p.: 1068C; IR (KBr) m (cm– 1): 3316 (NH stretch), 3052
(aromatic CH stretch), 1618 (C=N stretch), 1315 (C-N stretch),
1572, 1537, 1486 (C=C ring stretch), 1256 (asymmetric C-O-C
stretch), 1028 (symmetric C-O-C stretch); 1H-NMR d (ppm): 7.36-
7.37 (m, 2H, 1H of Ar & 1H of C-3 of furan), 7.73 (d, 1H of Ar),
6.65–6.70 (m, 2H of Ar), 7.91 (d, 1H, C-4 of furan), 5.59 (s, 1H, CH
in -CH-NH), 6.18-6.19 (m, 2H, 1H of NH in -NH-CH & 1H of NH in
NH-CH3), 2.83 (d, 3H, CH3 in NH-CH3); MS m/z: 334 [M]+, 336 [M]+2.
Anal. Calcd. for C14H12N5OS Cl: C, 50.38; H, 3.62; N, 20.98; S, 9.61.
Found: C, 50.24; H, 3.57; N, 20.81; S, 9.56. Rf value = 0.35.
3-(4-(N,N-Dimethyl amino) phenyl)-6-(1-methyl-pyrrol-2-
yl)-5,6-dihydro-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole 14a
Yield: 36%; m.p.: 1408C; IR (KBr) m (cm– 1): 3019 (aromatic CH
stretch), 1623 (C=N stretch), 2839 (methyl CH stretch), 1568,
1529, 1471 (C=C ring stretch), 1325 (C-N stretch); 1H-NMR d
(ppm): 6.84, 8.03 (d, 4H, Ar-H), 7.02 (d, 1H, C-5 of pyrrole), 6.58 (m,
1H, C-4 of pyrrole), 6.50 (d, 1H, C-3 of pyrrole), 5.57 (s, 1H, of -CH-
NH), 6.20 (bs, 1H of NH in -NH-CH), 3.56 (s, 3H, N-CH3), 3.01 (s, 6H,
N (CH3)2); MS m/z: 326 [M]+. Anal. Calcd. for C16H18N6S: C, 58.87; H,
5.56; N, 25.75; S, 9.82. Found: C, 58.69; H, 5.61; N, 25.86; S, 9.78.
Rf value = 0.47.
3-(Naphthyl-1-methyl)-6-[5-chloro-2-furanyl]-5,6-dihydro-
1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole 12c
Yield: 26%; m.p.: 948C; IR (KBr) m (cm– 1): 3168 (aromatic CH
stretch), 1621 (C=N stretching), 1554, 1520, 1475 (C=C ring
stretch), 2861 (methyl CH stretch), 1257 (asymmetric C-O-C
3-(2-(N-Methyl amino) phenyl)-6-(1-methyl-pyrrol-2-yl)-
5,6-dihydro-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole 14b
Yield: 41%; m.p.: 1928C; IR (KBr) m (cm– 1): 3215 (NH stretch), 3061
(aromatic CH stretch), 1619 (C=N stretch), 1321 (C-N stretch),
1584, 1518, 1468 (C=C ring stretch); 1H-NMR d (ppm): 7.36 (d, 1H
of Ar), 7.74 (d, 1H of Ar), 6.65–6.70 (m, 2H of Ar), 6.99 (d, 1H, C-5
of pyrrole), 6.60 (m, 1H, C-4 of pyrrole), 6.47 (d, 1H, C-3 of pyr-
role), 5.58 (s, 1H, of -CH-NH), 6.21 (bs, 1H, NH in -NH-CH), 3.56 (s,
3H, N-CH3), 6.18 (q, 1H, NH in NH-CH3), 2.83 (d, 3H, CH3 in NH-
CH3); MS m/z: 312 [M]+. Anal. Calcd. (%) for C15H16N6S: C, 57.67; H,
5.16; N, 26.90; S, 10.26. Found: C, 57.54; H, 5.18; N, 26.83; S,
10.28. Rf value = 0.38.
1
stretch), 1019 (symmetric C-O-C stretch); H-NMR d (ppm): 7.3–
8.1 (m, 9H, Ar-H), 5.56 (s, 1H, CH in -CH-NH), 6.198 (bs, 1H of NH
in -NH-CH), 4.52 (s, 2H, CH2); MS m/z: 369 [M]+, 371 [M]+2. Anal.
Calcd. for C18H13N4OSCl: C, 58.61; H, 3.55; N, 15.19; S, 8.69.
Found: C, 58.53; H, 3.51; N, 15.08; S, 8.64. Rf value = 0.18.
3-(4-(N,N-Dimethylamino)phenyl)-6-(1H-pyrrol-2-yl)-5,6-
dihydro-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole 13a
Yield: 45%; m.p.: 1628C; IR (KBr) m (cm– 1): 3351 (NH stretch), 3026
(aromatic CH stretch), 1614 (C=N stretch), 2837 (methyl CH
stretch), 1568, 1475 (C=C ring stretch), 1320 (C-N stretching); 1H-
NMR d (ppm): 6.81, 8.03 (d, 4H, Ar-H), 6.49 (d, 1H, C-3 of pyrrole),
6.60 (m, 1H of C-4 of pyrrole), 7.06 (d, 1H of C-5 of pyrrole), 9.81
(s, 1H, NH of pyrrole), 5.56 (s, 1H, CH in -CH-NH), 6.19 (bs, 1H of
NH in -NH-CH), 3.00 (s, 6H, N (CH3)2); MS m/z: 312 [M]+. Anal.
Calcd. for C15H16N6S: C, 57.67; H, 5.16; N, 26.90; S, 10.26. Found:
C, 57.53; H, 5.18; N, 27.03; S, 10.14. Rf value = 0.26.
3-(Naphthyl-1-methyl)-6-(1-methyl-pyrrol-2-yl)-5,6-
dihydro-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole 14c
Yield: 29%; m.p.: 1288C; IR (KBr) m (cm– 1): 3057 (aromatic CH
stretch), 1624 (C=N stretch), 1542, 1474 (C=C ring stretch), 2846
(methyl CH stretch); 1H-NMR d (ppm): 7.34–8.08 (m, 7H, Ar-H),
7.03 (d, 1H, C-5 of pyrrole), 6.57 (m, 1H, C-4 of pyrrole), 6.48 (d,
1H, C-3 of pyrrole), 5.57 (s, 1H, of -CH-NH), 6.20 (bs, 1H, NH in -NH-
CH), 3.56 (s, 3H, N-CH3), 4.51 (s, 2H, CH2); MS m/z: 347 [M]+. Anal.
Calcd. for C19H17N5S: C, 65.68; H, 4.93; N, 20.16; S, 9.23. Found: C,
65.57; H, 4.91; N, 20.08; S, 9.18. Rf value = 0.37.
3-(2-(N-Methylamino)-phenyl)-6-(1H-pyrrol-2-yl)-5,6-
dihydro-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole 13b
Yield: 41%; m.p.: 1468C; IR (KBr) m (cm– 1): 3359 (NH stretch), 3048
(aromatic CH stretch), 1618 (C=N stretch), 1317 (C-N stretch),
1581, 1537, 1492 (C=C ring stretch); 1H-NMR d (ppm): 7.38 (d, 1H
of Ar), 7.74 (d, 1H of Ar), 6.63–6.69 (m, 2H of Ar), 6.49 (d, 1H, C-3
of pyrrole), 6.59 (m, 1H of C-4 of pyrrole), 7.04 (d, 1H of C-5 of pyr-
role), 9.86 (s, 1H, NH of pyrrole), 5.54 (s, 1H, CH in -CH-NH), 6.18-
6.19 (m, 2H, 1H of NH in -NH-CH & 1H of NH in NH-CH3), 2.83 (d,
3H, CH3 in NH-CH3); MS m/z: 298 [M]+. Anal. Calcd. for C14H14N6S:
C, 56.36; H, 4.73; N, 28.17; S, 10.75. Found: C, 56.24; H, 4.68; N,
28.25; S, 10.82. Rf value = 0.39.
3-(4-(N,N-Dimethylamino)phenyl)-6-(1-phenyl-pyrrol-2-
yl)-5,6-dihydro-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole 15a
Yield: 34%; m.p.: 1708C; IR (KBr) m (cm– 1): 3075 (aromatic CH
stretch), 1627 (C=N stretch), 2839 (methyl CH stretch), 1579,
1546, 1463 (C=C ring stretch), 1329 (C-N stretch); 1H-NMR d
(ppm): 6.84, 8.02 (d, 4H, Ar-H), 7.07 (d, 1H, C-5 of pyrrole), 7.38 (s,
5H, C6H5 of N-C6H5), 6.54 (m, 1H, C-4 of pyrrole), 6.49 (d, 1H, C-3 of
pyrrole), 5.57 (s, 1H, of -CH-NH), 6.20 (bs, 1H, NH in -NH-CH), 3.01
(s, 6H, N (CH3)2); MS m/z: 388 [M]+. Anal. Calcd. (%) for C21H20N6S:
C, 64.92; H, 5.19; N, 21.63; S, 8.25. Found: C, 64.75; H, 5.24; N,
21.71; S, 8.18. Rf value = 0.18.
3-(Naphthalene-1-yl-methyl)-6-(1H-pyrrol-2-yl)-5,6-
3-(2-(N-Methylamino)phenyl)-6-(1-phenyl-pyrrol-2-yl)-
dihydro-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole 13c
Yield: 38%; m.p.: 1208C; IR (KBr) m (cm– 1): 3216 (NH stretch), 3079
(aromatic CH stretch), 1621 (C=N stretching), 1578, 1528, 1481
5,6-dihydro-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole 15b
Yield: 30%; m.p.: 1548C; IR (KBr) m (cm– 1): 3219 (NH stretch), 3047
(aromatic CH stretch), 1624 (C=N stretch), 1325 (C-N stretch),
1564, 1518, 1472 (C=C ring stretch); 1H-NMR d (ppm): 7.36 (d, 1H
of Ar), 7.38 (s, 5H, C6H5 of N-C6H5), 7.73 (d, 1H of Ar), 6.64–6.69
(m, 2H of Ar), 7.08 (d, 1H, C-5 of pyrrole), 6.57 (m, 1H, C-4 of pyr-
role), 6.49 (d, 1H, C-3 of pyrrole), 5.54 (s, 1H, of -CH-NH), 6.17-6.18
1
(C=C ring stretch), 2835 (methyl CH stretch); H-NMR d (ppm):
7.35–8.07 (m, 7H, Ar-H), 4.51 (s, 2H, CH2), 6.47 (d, 1H, C-3 of pyr-
role), 6.62 (m, 1H of C-4 of pyrrole), 7.05 (d, 1H of C-5 of pyrrole),
9.83 (s, 1H, NH of pyrrole), 5.56 (s, 1H, CH in -CH-NH), 6.19 (bs, 1H
of NH in -NH-CH); MS m/z: 333 [M]+. Anal. Calcd. for C18H15N5S: C,
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