Med Chem Res (2013) 22:4886–4892
4889
(d, 2Ar–H, J = 8.60 Hz), 3.82(s, 3H, OCH3); 13C
NMR(DMSO-d6):d 56.82, 119.12, 120.44, 120.68, 129.58,
130.42, 130.75, 131.76, 131.94, 134.92, 140.12, 148.62, 150.46
Mass: m/z 318.3 [M?]; Anal. Calcd. for C17H14N6O (318.3): C,
64.14; H, 4.43; N, 26.40. Found: C, 64.04; H, 4.88; N, 26.95.
d6):d 9.04(s,1H, NH in pyrazole ring), 7.02–8.06(m, 12H, Ar–
H); 13C NMR(DMSO-d6): 119.08, 120.20, 120.44, 120.86,
128.44, 129.36, 130.45, 130.86, 131.60, 131.86, 134.66,
139.32, 150.86; Mass: m/z 338.3 [M?]; Anal. Calcd. for
C20H14N6 (338.3): C, 70.99; H, 4.17; N, 24.84. Found: C,
71.24; H, 4.25; N, 24.65.
5-[3-(2-Methoxyphenyl)-1-phenyl-1H-pyrazol-4-yl]-
2H-tetrazole (4f)
Biological activity
Yellow powder; m.p.244–246 °C, yield, 60 % IR [KBr]
cm-1: 3,422, 1,649, 1,593, 1,506, 1,238, 1,162;1H NMR
(DMSO-d6): d 9.18(s, 1H, NH in pyrazolering), 8.16 (d, 2Ar–
H, J = 7.82 Hz), 7.84 (d, 2Ar–H, J = 8.96 Hz), 7.66 (t, 2Ar–
H, J = 8.12 Hz), 7.39 (t, 1Ar–H, J = 7.47 Hz) , 7.03 (d,
2Ar–H, J = 8.68 Hz), 3.86(s, 3H, OCH3); 13C NMR(DMSO-
d6):d 55.68,119.14,120.44,120.67, 129.68, 130.67, 130.86,
131.26, 131.98, 134.56, 139.66, 151.46 Mass: m/z 318.3
[M?]; Anal. Calcd. for C17H14N6O (318.3): C, 64.14; H, 4.43;
N, 26.40. Found: C, 64.10; H, 4.62; N, 26.66.
Anti-inflammatory activity
Adult albino rats of both sexes weighing between 120 and
150 g were used and divided into 11 groups of six animals
each. The control group was given 1 % aq. CMC. Dic-
lofenac sodium (20 mg/kg, standard) and test compounds
(4a–i, 20 mg/kg) in 1 % aq. CMC were administered orally
1 h before induction of inflammation. Induction of inflam-
mation was performed by s.c injection of 0.1 ml of freshly
prepared 1 % carrageenan in saline solution, into the sub-
plantar region of the right hind paw. The paw volume was
measured using the plethysmometer at 0.5, 1, 2, 3 h after the
carrageenan challenge. The average value of edema was
calculated by taking the average of six animals at different
hours. Percentage inhibition of edema was calculated for
each group with respect to the control group.
4-[1-Phenyl-4-(2H-tetrazol-5-yl)-1H-pyrazol-3-yl]
phenol (4g)
Brown powder; m.p.250–252 °C, yield, 55 %.IR[KBr]
1
cm-1: 3,442, 3,316, 1,657, 1,596, 1,519; H NMR (DMSO-
d6): d 9.14 (s, 1H, NH in pyrazole ring), 7.98 (d, 2H,
J = 7.85 Hz, Ar–H), 7.82 (d, 2H, J = 8.60 Hz, Ar–H), 7.76
(t, 2H, J = 7.82 Hz, Ar–H), 7.56 (d, 2H, J = 8.21 Hz, Ar–
H), 7.43 (t, 1H, J = 7.43 Hz, Ar–H); 13C NMR(DMSO-d6):d
119.23, 120.28, 120.88, 130.08, 130.66, 130.89, 131.22,
131.86, 134.12, 139.86, 146.12, 150.35; Mass: m/z 304.3
[M?]. Anal. Calcd. for C16H12N6O (304.30): C, 63.15; H,
4.17; N, 24.84. Found: C, 63.74; H, 4.98; N, 23.65.
Inflammation was expressed as the change in paw
volume
Edema ¼ Tt ꢁ T0
where
T0 Volume at ‘0’ h
Tt Volume at ‘t’ h
2-[1-Phenyl-4-(2H-tetrazol-5-yl)-1H-pyrazol-3-yl]
Percentage reduction ¼ ðV0 ꢁ VtÞ=V0 ꢂ 100
where,
phenol (4h)
Brown powder; m.p.254–256 °C, yield, 50 %.IR[KBr]
V0 Volume of the paw of control at time ‘t’
1
cm-1: 3,412, 3,386, 1,649, 1,598, 1,509; H NMR(DMSO-
Vt Volume of the paw of drug treated at time ‘t’
d6): d 9.12 (s, 1H, NH in pyrazole ring), 7.89 (d, 2H,
J = 7.88 Hz, Ar–H), 7.84 (d, 2H, J = 8.65 Hz, Ar–H), 7.72
(t, 2H, J = 7.86 Hz, Ar–H), 7.48 (d, 2H, J = 8.28 Hz, Ar–
H), 7.44 (t, 1H, J = 7.46 Hz, Ar–H);13C NMR(DMSO-d6):d
119.03,120.42, 120.58, 130.18, 130.86, 130.92, 131.42,
131.66, 134.32, 139.87, 148.22, 150.85; Mass: m/z 304.3
[M?]. Anal. Calcd. for C16H12N6O (304.3): C, 63.15; H,
4.17; N, 24.84. Found: C, 63.46; H, 4.84; N, 23.64.
Acute ulcerogenicity study
Young adult albino rats weighing 180–220 g were used for
the experiment, and animals were divided into groups of six
animals each. Rats were fasted 20 h before drug adminis-
tration. The test compounds, diclofenac sodium and cele-
coxib, were given orally in doses of 100, 50, and 50 mg/kg,
respectively, while the control group received only vehicle,
i.e., 1 % CMC. Rats were fasted for 2 h, allowed to feed for
2 h, and then fasted for another 20 h. Rats were given
another two doses in the second and third day. In the fourth
day, rats were sacrificed, the stomach was removed, opened
5-[3-(2-Naphthyl)-1-phenyl-1H-pyrazol-4-yl]-2H-
tetrazole (4i)
Lightbrown powder; m.p. 250–252 °C, yield, 55 %. IR[KBr]
1
cm-1: 3,426, 1,648, 1,596, 1,500, 1,443; H NMR(DMSO-
123