Med Chem Res
anal C16H15N3O3 calcd. C, 64.64, H, 5.09, N, 14.13. Found
C, 64.56, H, 5.06, N, 14.08.
anal C16H15N3O2 calcd. C, 68.31, H, 5.37, N, 14.94. Found
C, 68.26, H, 5.15, N, 14.67.
1-(2-(3-Chloro-4-nitrophenyl)-5-(pyridine-3-yl)-1,3,4-
1-(2-(3,4-Dimethoxyphenyl)-5-(pyridine-3-yl)-1,3,4-
oxadiazole-3(2H)-yl) ethanone (6f)
oxadiazole-3(2H)-yl) ethanone (6j)
Yield: 68%; mp 182–184 °C; IR (KBr) νmax: 3000, 2900,
Yield: 63%; mp 140–142 °C; IR (KBr) νmax:: 3210, 2915,
1
1700, 1640, 1596, 1468, 1423, 1375, 738 cm−1; H NMR
1698, 1652, 1596, 1417, 1373, 1301 cm−1 1H NMR
;
(DMSO-d6, 400 MHz): 7.6–9.2 (m, 7H), 8.1 (s, 1H), 2.4 (s,
3H); 13C NMR (DMSO-d6, 100 MHz) δ: 23.4 (CH3), 74.0
(CH), 122.3 (CH), 123.9 (CH), 126.0 (CH), 126.3 (C),
127.7 (CH), 128.7 (C), 137.2 (CH), 151.5 (CH), 152.0
(CH), 155.0 (C), 146.8 (C), 147.9 (C), 168.6 (C); EIMS m/z
346.22 (M+); anal C15H11ClN4O4 calcd. C, 51.96, H, 3.2,
N, 16.16. Found C, 51.85, H, 3.1, N, 16.04.
(DMSO-d6, 400 MHz): 7.5–9.2 (m, 7H), 8.1 (s, 1H), 2.4 (s,
3H), 3.6 (s, 6H); 13C NMR (DMSO-d6, 100 MHz) δ: 23.4
(CH3), 56.2 (CH3), 74.8 (CH), 112.2 (CH), 115.1 (CH),
120.3 (CH), 123.9 (CH), 126.3 (C), 133.7 (C), 137.2 (CH),
147.8 (C), 149.6 (C), 151.5 (CH), 152.0 (CH), 155.0 (C),
168.6 (C); EIMS m/z 327.92 (M+); Anal C17H17N3O4
calcd. C, 62.38, H, 5.23, N, 12.84. Found C, 62.29, H, 5.11,
N, 12.74.
1-(2-(3-Nitro-phenyl)-5-pyridine-3-yl-(1,3,4) oxadiazol-3-
yl) ethanone (6g)
Antimicrobial activity
Yield: 66%; mp 191–193 °C; IR (KBr) νmax: 3195, 2923,
1682, 1651, 1596, 1475, 1387 cm−1; 1H NMR (DMSO-d6,
400 MHz): 7.2–9.2 (m, 8H), 8.1 (s, 1H), 2.4 (s, 3H); 13C
NMR (DMSO-d6, 100 MHz) δ: 23.4 (CH3), 73.5 (CH),
119.1 (CH), 122.2 (CH), 123.9 (CH), 126.3 (C), 129.5
(CH), 133.1 (CH), 137.2 (CH), 141.3 (C), 148.2 (C), 151.5
(CH), 152.0 (CH), 155.0 (C), 168.6 (C); EIMS m/z 312.88
(M+); anal C15H12N4O4 calcd. C, 57.69, H, 3.87, N, 17.94.
Found C, 57.61, H, 3.79, N, 17.85.
The cup-plate method was adopted in the present investi-
gation. Briefly, the nutrient agar medium, containing stan-
dard bacterial inoculums was filled in cups or disks of
standard diameter. After introducing the test compounds
into the disks, the diameter of zone of inhibition was
measured. All synthesized compound were dissolved in
dimethyl formamide (DMF) to form the concentration of
125, 250, and 500 μg/mL. Ciprofloxacin and ketoconazole
were used as the standard for antibacterial and antifungal
studies, respectively.
1-(2-(4-Hydroxy-3-methoxyphenyl)-5-(pyridine-3-yl)-1,3,4-
oxadiazole-3(2H)-yl)ethanone (6h)
Antibacterial activity
Yield: 64%; mp 150–152 °C; IR (KBr) νmax: 3383, 3063,
Different microorganisms like S. aureus, B. aureus, E. coli,
and P. aeruginosa used for determining the anti-bacterial
activity of synthesized compounds were confirmed by
biochemical test and maintained on nutrient agar (Muller
Hinton Agar, HiMedia, Mumbai) slopes at pH 7.4. Briefly
the required amount of test solution (40 μL of each tested
concentration of synthesized compounds) and standard
solution (40 μL) were added into each cup and kept
undisturbed for at least 2 h at room temperature to allow
proper diffusion of the test and standard solution into the
nutrient agar medium. The petri plates were incubated at 37
1 °C for 24 h and the diameter of zone of inhibition was
measured. Simultaneously controls were maintained using
DMF for the observation of solvent effects.
1
2957, 1698, 1651, 1596, 1475, 1374, 1304, 1202 cm−1; H
NMR (DMSO-d6, 400 MHz): 7.6–9.2 (m, 7H), 8.1 (s, 1H),
2.4 (s, 3H), 2.1 (s, 1H), 3.8 (s, 3H);13C NMR (DMSO-d6,
100 MHz) δ: 23.4 (CH3), 56.2 (CH3), 74.8 (CH), 112.4
(CH), 116.7 (CH), 120.7 (CH), 123.9 (CH), 126.3 (C),
134.0 (C), 137.2 (CH), 143.7 (C), 151.2 (C), 151.5 (CH),
152.0 (CH), 155.0 (C), 168.6 (C); EIMS m/z 313.09 (M+);
anal C16H15N3O4 calcd. C, 61.34, H, 4.83, N, 13.41. Found
C, 61.24, H, 4.76, N, 13.34.
1-(5-Pyridine-3-yl)-2-p-tolyl-1,3,4-oxadiazole-3(2H)-yl)
ethanone (6i)
Yield: 65%; mp 157–159 °C; IR (KBr) νmax: 3212, 3010,
1699, 1636, 1574, 1418, 1361, 1293 cm−1
;
1H NMR
Antifungal activity
(DMSO-d6, 400 MHz): 7.3–9.2 (m, 8H), 8.1 (s, 1H), 2.3 (s,
3H), 2.4 (s, 3H); 13C NMR (DMSO-d6, 100 MHz) δ: 23.4
(CH3), 24.3 (CH3), 74.5 (CH), 123.9 (CH), 126.9 (CH),
126.3 (C), 128.9 (CH), 136.4 (C), 137.2 (CH), 151.5 (CH),
152.0 (CH), 155.0 (C), 168.6 (C); EIMS m/z 281.42 (M+);
Fungi C. albicans and A. niger were employed for the
estimation of antifungal activity of synthesized compounds.
Sabouraud dextrose agar (SDA; HiMedia, Mumbai) was
used for the cultivation of fungi, particularly pathogenic