Month 2019
Synthesis, Antimicrobial, and Antioxidant Screening of 1,2,4-Triazolo-1,3,4-
Thiadiazole Derivatives
1
1
str), 692 (C-S-C str); H-NMR (CDCl3) δ (ppm): 4.5 (s,
2H, CH2), 7.2–7.4 (m, 5H, ArH), 7.6–7.8 (m, 3H, ArH);
MS (m/z): 371.9933 (M+), 373.9939 (M + 2); Anal.
Calcd for C16H10ClN5O2S (371.80): C, 51.69; H, 2.71;
N, 18.84. Found: C, 51.64; H, 2.68; N, 18.80.
str); H-NMR (CDCl3) δ (ppm): 3.7 (d, 3H, CH3), 4.45
(s, 2H, CH2), 5.0 (s, 1H, CH), 7.2–7.4 (m, 10H, ArH),
7.49–7.56 (m, 4H, ArH); MS (m/z): 412.9383 (M+),
414.8918 (M + 2); Anal. Calcd for C24H20N4OS
(412.50): C, 69.88; H, 4.89; N, 13.58; O, 3.88. Found: C,
69.82; H, 4.85; N, 13.63; O, 3.93.
6-Benzhydryl-3-benzyl-[1,2,4]triazolo[3,4-b][1,3,4]
thiadiazole (TH-2).
Yield 81.4%; mp: 140–142°C; IR
6-(2,4-Dichlorobenzyl)-3-(4-methoxybenzyl)-[1,2,4]
(KBr, cmꢀ1): 3019 (C-H str, Ar), 1629 (C=N str) 1598
triazolo[3,4-b][1,3,4]thiadiazole (TH-8).
Yield 83%; mp:
1
(C=C str, Ar), 1511 (C-N str), 695 (C-S-C str); H-NMR
168–170°C; IR (KBr, cmꢀ1): 3064, 3002 (C-H str, Ar),
(CDCl3) δ (ppm): 4.6 (s, 2H, CH2), 5.8 (s, 1H, CH), 7.2–
7.5 (s, 15H, ArH); MS (m/z): 382.9834 (M+); Anal.
Calcd for C23H18N4S (382.48): C, 72.22; H, 4.74; N,
14.65. Found: C, 72.18, H, 4.76, N, 14.61.
1611 (C=N str), 1585 (C=C str, Ar), 1255, 1036 (C-O-C
str), 739 (C-Cl str), 684 (C-S-C str); H-NMR (CDCl3) δ
1
(ppm): 2.9–3.0 (s, 2H, CH2), 3.7 (s, 3H, CH3), 4.3–4.5
(d, 2H, CH2), 6.8 (m, 3H, ArH), 7.2–7.3 (m, 4H, ArH);
MS (m/z): 404.9604 (M+); Anal. Calcd for
C18H14Cl2N4OS (405.30): C, 53.34; H, 3.48; N, 13.82;
O, 3.95. Found: C, 53.29; H, 3.43; N, 13.87; O, 3.99.
3-(4-Methoxybenzyl)-6-nonyl-[1,2,4]triazolo[3,4-b][1,3,4]
thiadiazole (TH-9). Yield 75%; mp: 56–58°C; IR (KBr,
6-(2,4-Dichlorobenzyl)-3-benzyl-[1,2,4]triazolo[3,4-b][1,3,4]
thiadiazole (TH-3).
Yield 69.3%; mp: 162–164°C; IR
(KBr, cmꢀ1): 3020 (C-H str, Ar), 1618 (C=N str), 1576
1
(C=C str, Ar), 733 (C-Cl str), 704 (C-S-C str); H-NMR
(CDCl3) δ (ppm): 3.6 (s, 2H, CH2), 4.1–4.3 (t, 2H,
CH2), 6.9–7.1 (m, 5H, ArH), 7.2 (m, 3H, ArH); MS
(m/z): 374.9303 (M+). Anal. Calcd for C17H12Cl2N4S
(375.27): C, 54.41; H, 3.22; N, 14. Found: C, 54.45;
cmꢀ1): 3002 (C-H str, Ar), 1611 (C=N str), 1580 (C=C
str, Ar), 1465 (C-H bend, CH2), 1375 (C-H bend,
CH3), 1251, 1031 (C-O-C str), 692 (C-S-C str); 1H-
NMR (CDCl3) δ (ppm): 0.86–0.89 (d, 3H, CH3), 1.2
(s, 2H, CH2), 1.3–1.4 (t, 4H, CH2), 1.6 (t, 2H, CH2),
1.7–1.8 (t, 2H, CH2), 2.1 (s, 2H, CH2), 2.3 (t, 2H,
CH2), 2.9 (t, 2H, CH2), 3.77–3.83 (q, 3H, CH3), 4.3 (s,
2H, CH2), 7.2–7.3 (m, 4H, ArH); MS (m/z): 372.9270
(M+); Anal. Calcd for C20H28N4OS (372.52): C, 64.48;
H, 7.58; N, 15.04; O, 4.29. Found: C, 64.44; H, 7.62;
H, 3.20; N, 14.90.
3-Benzyl-6-nonyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole
(TH-4). Yield 76%; mp: 58–60°C; IR (KBr, cmꢀ1): 3025
(C-H str, Ar), 1655 (C=N str), 1646 (C-N str), 1560 (C=C
band, Ar), 1465 (C-H bend, CH2), 1375 (C-H bend, CH3),
1
696 (C-S-C str); H-NMR (CDCl3) δ (ppm): 0.8–0.9 (t,
3H, CH3), 1.27–1.40 (t, 8H, CH2), 1.8 (t, 2H, CH2), 2.17
(s, 2H, CH2), 3.0 (s, 2H, CH2), 4.1 (s, 2H, CH2), 4.5 (s,
2H, CH2), 7.2–7.4 (m, 5H, ArH); MS (m/z): 342.9183 (M
+); Anal. Calcd for C19H26N4S (342.50): C, 66.63; H,
7.65; N, 16.36. Found: C, 66.60; H, 7.61; N, 16.41.
3-Benzyl-6-(4-fluorophenyl)-[1,2,4]triazolo[3,4-b][1,3,4]
N, 15.09; O, 4.33.
3-(4-Methoxybenzyl)-6-(4-fluorophenyl)-[1,2,4]triazolo[3,4-
b][1,3,4]thiadiazole (TH-10). Yield 69%; mp: 130–132°C,
IR (KBr, cmꢀ1): 3014 (C-H str, Ar), 1604 (C=N str), 1546
(C=C str, Ar), 1515 (C-N str), 1251, 1032 (C-O-C str),
1104 (C-F str), 692 (C-S-C str); 1H-NMR (CDCl3) δ
(ppm): 3.77 (s, 3H, CH3), 4.49 (s, 2H, CH2), 6.8 (m, 4H,
ArH), 7.1–7.2 (m, 4H, ArH); MS (m/z): 340.9981 (M+);
Anal. Calcd for C17H13FN4OS (340.37): C, 59.99; H,
3.85; N, 16.46; O, 4.70. Found: C, 59.94; H, 3.82; N,
thiadiazole (TH-5).
Yield 71.2%; mp: 164–166°C; IR
(KBr, cmꢀ1): 3081 (C-H str, Ar), 1656 (C=N band),
1
1562 (C=C str, Ar), 1528 (C-N str), 693 (C-S-C str); H-
NMR (CDCl3) δ (ppm): 4.4–4.5 (d, 2H, CH2), 7.4–7.3
(m, 5H, ArH), 7.4 (m, 4H, ArH); MS (m/z): 309.9961 (M
+), 311.9922 (M + 2); Anal. Calcd for C16H11FN4S
(310.34): C, 61.92; H, 3.57; N, 18.05. Found: C, 61.87;
16.49; O, 4.73.
3-(4-Chlorobenzyl)-6-(2-chloro-5-nitrophenyl)-[1,2,4]
triazolo[3,4-b][1,3,4]thiadiazole (TH-11). Yield 80%; mp:
H, 3.55; N, 18.11.
142–144°C; IR (KBr, cmꢀ1): 3067 (C-H str, Ar), 1608
3-(4-Methoxybenzyl)-6-(2-chloro-5-nitrophenyl)-[1,2,4]
triazolo[3,4-b][1,3,4]thiadiazole (TH-6). Yield 71.4%; mp:
(C=N str), 1568, 1344 (-NO2 str), 1525 (C-N str), 742
164–166°C; IR (KBr, cmꢀ1): 3065 (C-H str, Ar), 1608
(C-Cl str), 689 (C-S-C str); H-NMR (CDCl3) δ (ppm):
1
(C=N band), 1569, 1343 (-NO2 str), 1243, 1031 (C-O-C
str), 744 (C-Cl str), 695 (C-S-C str); H-NMR (CDCl3) δ
(ppm): 3.78 (s, 3H, CH3), 4.5 (s, 2H, CH2), 6.88–6.90
(m, 3H, ArH), 7.2–7.4 (m, 4H, ArH); MS (m/z):
401.9901 (M+); Anal. Calcd for C17H12ClN5O3S
(401.82): C, 50.81; H, 3.01; N, 17.43; O, 11.94. Found:
4.5 (d, 2H, CH2), 7.3 (m, 3H, ArH), 7.4 (m, 4H, ArH);
MS (m/z): 406.9921 (M+); Anal. Calcd for
C16H9Cl2N5O2S (406.24): C, 47.30; H, 2.23; N, 17.24;
1
O, 7.88. Found: C, 47.34; H, 2.21; N, 17.19; O, 7.91.
3-(4-Chlorobenzyl)-6-benzhydryl-[1,2,4]triazolo[3,4-b][1,3,4]
thiadiazole (TH-12). Yield 83%; mp: 64–66°C; IR (KBr,
cmꢀ1): 3058, 3025 (C-H str, Ar), 1615 (C=N str), 1580
(C=C str, Ar), 1516 (C-N str), 747 (C-Cl str), 699 (C-S
C, 50.78; H, 2.97; N, 17.49; O, 11.90.
3-(4-Methoxybenzyl)-6-benzhydryl-[1,2,4]triazolo[3,4-b]
[1,3,4]thiadiazole (TH-7). Yield 77.3%; mp: 128–130°C;
1
str); H-NMR (CDCl3) δ (ppm): 4.6 (d, 2H, CH2), 5.7
IR (KBr, cmꢀ1): 3028 (C-H str, Ar), 1610 (C=N str),
1590 (C=C str, Ar), 1249, 1030 (C-O-C str), 698 (C-S-C
(s, 1H, CH), 7.1–7.4 (m, 14H, ArH); MS (m/z):
418.9903 (M + 2); Anal. Calcd for C23H17ClN4S
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet