Synthesis anti-fungal and anti-bacterial screening of 3-phenyl-1,4,5-trihydro-pyrazol and 2, 4-dihydro[1,2,4]-triazol-3-one derivatives of 4-hydroxy-2-oxo-2H-1-benzopyran

Article abstract of DOI:10.1002/jhet.5570400231

4-Hydroxy-2-oxo-2H-1-benzopyran-3-carboxaldehydes 2a-d are prepared from 4-hydroxy-2-oxo-2H-1-benzopyrans 1a-d via the Vielsmeyer Haack reaction. The 4-hydroxy-2-oxo-3-(3′oxo-3′-phenylprop-1′-enyl)- 2H-1-benzopyrans 3a-d are obtained from 2a-d via the Cla

Full text of DOI:10.1002/jhet.5570400231

Mar-Apr 2003
Synthesis Anti-fungal and Anti-bacterial Screening of
3-Phenyl-1,4,5-trihydro-pyrazol and 2, 4-Dihydro[1,2,4]-
triazol-3-one Derivatives of 4-Hydroxy-2-oxo-2H-1-benzopyran
377
V. V. Mulwad and Jyoti M. Shirodkar
Department of Organic Chemistry, Institute of Science,
15, Madam Cama Road, Mumbai 400032, India.
Received November 26, 2001
Received Revised November 25, 2002
4-Hydroxy-2-oxo-2H-1-benzopyran-3-carboxaldehydes 2a-d are prepared from 4-hydroxy-2-oxo-2H-1-
benzopyrans 1a-d via the Vielsmeyer Haack reaction. The 4-hydroxy-2-oxo-3-(3'oxo-3'-phenylprop-1'-
enyl)-2H-1-benzopyrans 3a-d are obtained from 2a-d via the Claisen reaction. Refluxing compounds 3a-d
with hydrazine hydrate gave the 3-phenyl-5-(4-hydroxy-2-oxo-2H-1-benzopyran-3-yl)-1,4,5-trihydropyra-
zols 4a-d. Stirring compounds 2a-d with semicarbazide hydrochloride in acidic medium gave the
4-hydroxy-2-oxo-2H-1-benzopyran-3-aldehyde-semicarbazone 5a-d, which on cyclisation with ferric chlo-
ride hexahydrate gave the 5-(4-hydroxy-2-oxo-2H-1-benzopyran-3-yl)-2,4-dihydro[1,2,4]triazol-3-ones
6a-d. All these compounds show significant antibacterial activities.
J. Heterocyclic Chem., 40, 377 (2003).
Introduction.
flammatories, antirheumatic etc. The 4-hydroxy-2-oxo-3-
(3'oxo-3'-phenylprop-1'-enyl)-2H-1-benzopyran
(Chalcone) 3a–d are cyclised to the 3-phenyl-5-(4-
hydroxy-2-oxo-2H-1-benzopyran-3-yl)-1,4,5-trihydro-
pyrazols 4a-d by refluxing with methanol and hydrazine
hydrate. The structure of these compounds has been con-
firmed by spectral and analytical data.
Various semicarbazones [18] are known to possess anti-
inflammatory, analgesic and antibacterial activity.
4-Hydroxy-2-oxo-2H-1-benzopyran-3-aldehyde-semicar-
bazone 5a-d have been prepared by using 4-hydroxy-2-
oxo-2H-1-benzopyran-3-carboxaidehyde 2a-d and semi-
carbazide hydrochloride in ethanol. These compounds
give smell of ammonia on boiling with NaOH. The struc-
ture of compounds 5a-5d has been confirmed by spectral
and analytical data.
1,2,4-Triazoles display a wide range of pharmacological
activity [19-22]. Hence, semicarbazones 5a-d were
refluxed with an ethanolic solution of ferric chloride hexa-
hydrate to give 5-(4-hydroxy-2-oxo-2H-1-benzopyran-3-
yl)-2,4-dihydro[1,2,4]triazol-3-ones 6a-d. These com-
pounds do not smell of ammonia on boiling with NaOH
and structure of compounds 6a-d have been confirmed by
spectral and analytical data.
Benzopyrans show activities such as antifungal [1], anti-
coagulant [2], antibacterial [3] and insecticide [4]. The bio-
logical importance and considerable therapeutic potential
of 3-substituted-4-hydroxybenzopyrans generate consider-
able interest to us in designing the synthesis of number of
3-substituted-4-hydroxybenzopyrans which act as possible
HIV protease inhibitors with a high therapeutic index [5].
Various workers have reported the synthesis of
4-hydroxy-2-oxo-2H-1-benzopyran-3-carboxaldehyde.
However the yield obtained was poor [6,7]. Here we report
the synthesis of 4-hydroxy-2-oxo-2H-1-benzopyran-3-car-
boxaldehyde 2a-d via the Veilsmeyer Haack reaction by
refluxing 4-hydroxy-2-oxo-2H-1-benzopyran [8] 1 with
dimethyl formamide and phosphorous oxychloride. The
yield obtained by our method is much higher than reported
earlier. Compounds 2a–d do not show positive Beilstein
and Lassignes sodium fusion tests, indicating the absence
of halogen. Compounds 2a-d forms its 2,4–dinitrophenyl-
hydrazine derivative verifying the presence of the carbonyl
group, and the structure of 4-hydroxy-2-oxo-2H-1-ben-
zopyran-3-carboxaldehyde has been confirmed by spectral
and analytical data.
Chalcones are known to possess acute anti-inflamma-
tory [9a,9b], antibacterial [10,11a,11b,11c,12] and antifun-
gal [10,12,13a,13b,13c,13d] effects. Thus, the 4-hydroxy-
2-oxo-2H-1-benzopyran-3-carboxaldehydes are converted
into corresponding 4-hydroxy-2-oxo-3-(3'oxo-3'-phenyl-
prop-1'-enyl)-2H-1-benzopyrans 3a-d via the Claisen reac-
tion by refluxing with the appropriate aromatic ketones,
using 10% NaOH. These chalcones give coloration with
ferric chloride. The formation of these chalcones has also
confirmed by spectral and analytical data and also through
its dibromo derivatives.
Biological Screening.
Compounds 3c, 4a, 4b, 4c, 4d, 5b, 6a, 6b, 6c and 6d
were screened for their antibacterial activity against both
gram-positive and gram-negative bacteria as shown in
Table I. Minimum inhibitory concentration (MIC) of these
compounds was determined by tube dilution method [23]
using sodium penicillin (3.3 µgm/ml), trimethoprim (2.7
µgm/ml) as standards in DMF solvent. Compounds 3b, 4d,
5b, 6b were screened for antifungal activity against C.
albicans, T. mentagrophytes and T. rubrum however they
did not show any significant antifungal activity up to 200
µgm/ml.
Pyrazoline derivatives are known to possess biological
activities [14-17] such as analgesic, antipyretics, antiin-

378
V. V. Mulwad and J. M. Shirodkar
Vol. 40
against S. typhi and S. aureus respectively. Compounds 6a
R , R , R =H and 6b R = CH showed antibacterial activ-
1
2
3
1
3
ity at 100 µgm/ml against S. typhi and S. aureus respec-
tively. While compounds 6c R = CH and 6d R = CH
3
2
3
3
showed antibacterial activity at 100 µgm/ml against S.
typhi and 50 µgm/ml against S. aureus respectively.
EXPERIMENTAL
General.
Melting points were determined in open capillaries and are
uncorrected. The IR spectra were recorded on Perkin –Elmer 257
1
spectrophotometer using KBr disks. H NMR spectra were
recorded on VXR-300 spectrometer, the chemical shifts are given
in δ (ppm) downfield from internal standard tetramethylsilane
(TMS) and coupling constants are given in Hz. The homogeneity
of compounds were measured by TLC on silica gel plates where
the spots were developed in an iodine chamber.
4-Hydroxy-2-oxo-2H-1-benzopyran-3-carboxaldehydes (2a-d).
Phosphorous oxychloride (2 ml) was added to 1 (0.01 mol) in
dimethyl formamide (20 ml). The mixture was refluxed for 9 hrs;
then it was poured into a saturated solution of sodium acetate.
The resulting solid was collected by filtration and recrystallized
form ethanol.
4-Hydroxy-2-oxo-2H-1-benzopyran-3-carboxaldehyde (2a).
Compound 2a was obtained in 72% yield; mp: 135-136 °C; IR
-1
(KBr): 3421(-OH), 1720 (>C=O), 1670(>C=O), 1600, 1375cm ;
1
H NMR: δ 7.20-7.80 (m, 4H, aromatic-H), δ 8.00 (s, 1H, -CHO)
and δ 10.00 (s, 1H, -OH, D O exchangeable). Its 2,4-DNP deriv-
2
1a, 2a, 3a, 4a, 5a, 6a:R =R =R =H
1
2
3
ative: mp: 278 °C. IR (KBr): 3435 (-OH, -NH), 1730(>C=O),
1b, 2b, 3b, 4b, 5b, 6b: R =CH , R =R =HP
1
3
2
3
-1
1659, 1622, 1445, 1385 cm .
1c, 2c, 3c, 4c, 5c, 6c: R =CH , R =R =H
2
3
1
3
1c, 2c, 3c, 4c, 5c, 6c: R =CH , R =R =H
Anal. Calcd. For C H O : C, 63.16; H, 3.15. Found:C, 63.12;
3
3
1
2
10
6 4
H, 3.17.
Table I shows that compound 4a R , R , R =H is more
active than compounds 4b, 4c and 4d and that 4a show
4-Hydroxy-6-methyl-2-oxo-2H-1-benzopyran-3-carboxaldehyde
(2b).
1
2
3
antibacterial activity at 50 µgm/ml against S. typhi and S.
Compound 2b was obtained in 74% yield; mp: 173-174 °C. IR
aureus respectively. Compounds 4b R = CH and 4c R =
1
3
2
(KBr): 3429(-OH), 2922 (-CH stretching), 1720 (>C=O), 1685
-1
1
CH showed antibacterial activity at 100 µgm/ml against
(>C=O), 1623, 1575, 1499, 1374cm ; H NMR: δ 2.40 (s, 3H,
3
S. typhi and at 50 µgm/ml against S. aureus. Compound 4d
CH ), δ 7.20-7.80 (m, 3H, aromatic-H), δ 7.95 (s, 1H, -CHO) and
3
δ 9.60 (s, 1H, -OH, D O exchangeable).
R = CH showed antibacterial activity at 100 µgm/ml
2
3
3
Anal. Calcd. For C H O : C, 64.70; H, 3.92. Found:C, 64.65;
11
8 4
H, 3.95.
Table
I
4-Hydroxy-7-methyl-2-oxo-2H-1-benzopyran-3-carboxaldehyde
(2c).
Minimum Inhibitory Concentration
Sr. NO.
R , R , R
3
S. typhi
S. aureus
1
2
Compound 2c was obtained in 73% yield; mp: 192-193 °C; IR
(KBr): 3426 (-OH), 2925 (-CH stretching), 1716 (>C=O),
1689(>C=O), 1609, 1523, 1376 cm ; H NMR: δ 2.3 (s, 3H,
3c
4a
4b
4c
4d
5b
6a
6b
6c
6d
R =CH
+++
++
+
+
+
+
+
+
+
+
2
3
-1
1
R , R , R =H
++
++
++
+
+
+
+
++
++
1
2
3
R =CH
CH ), δ 7.2-8 (m, 3H, aromatic-H), δ 7.89 (s, 1H, -CHO) and δ
1
3
3
3
3
3
R =CH
9.9 (s, 1H, -OH, D O exchangeable).
2
2
R =CH
3
Anal. Calcd. For C H O : C, 64.70; H, 3.92. Found:C, 64.64;
11
8 4
R =CH
1
H, 3.95.
R , R , R =H
1
2
3
R =CH
4-Hydroxy-8-methyl-2-oxo-2H-1-benzopyran-3-carboxaldehyde
(2d).
1
3
3
3
R =CH
2
R =CH
+
3
Compound 2d was obtained in 74% yield; mp: 232-233 °C; IR
Note: + =100mgm/ML, ++ =50mgm/ML, +++ =10mgm/ML
(KBr): 3420 (-OH), 2927 (-CH stretching), 1720(>C=O),

Mar-Apr 2003
Synthesis Anti-fungal and Anti-bacterial Screening of 3-Phenyl-1,4,5-trihydro-pyrazol
379
-1
1
1700(>C=O), 1600, 1383 cm ; H NMR: δ 2.2 (s, 3H, CH ), δ
reaction mixture was refluxed for 5 hrs. On cooling solid
obtained was collected by filtration, washed with water and
recrystallized from ethanol.
3
7.3-8 (m, 3H, aromatic-H), δ 8.3 (s, 1H, -CHO) and δ 9.8 (s, 1H,
-OH, D O exchangeable).
2
Anal. Calcd. For C H O : C, 64.70; H, 3.92. Found: C, 64.69;
H, 3.91.
11
8 4
3-Phenyl-5-(4-hydroxy-2-oxo-2H-1-benzopyran-3-yl)-1,4,5-tri-
hydro-pyrazol (4a).
4-Hydroxy-2-oxo-3-(3'oxo-3'-phenylprop-1'-enyl)-2H-1-ben-
zopyrans (3a-d).
Compound 4a: was obtained in 55% yield; mp:>260 °C; IR
-1
1
(KBr): 3424 (-OH, -NH), 1720 (>C=O), 1615, 1340 cm ;
H
To solution of 2 (0.01 mol) in ethanol (20 ml), acetophenone
(0.01 mol) and 10% NaOH were added and the mixture was
stirred for 2 hrs. Then the reaction mixture was refluxed for an
additional 6 hrs and neutralized with dilute HCl resulting in a
sticky mass that on treatment with acetic acid gave a solid, which
was recrystallized from dilute acetic acid.
NMR (DMSO-d ): δ 2.70 (d, 2H, C -H), δ 4.80 (t, 1H, C -H), δ
6
4
5
7.00-7.70 (m, 9H, aromatic-H), δ 7.90 (broad, 1H, NH, D O
2
exchangeable) and δ 9.80 (s, 1H, OH, D O exchangeable).
2
Anal. Calcd. For C
H
N O : C, 70.59; H, 4.57; N, 9.15.
18 14 2 3
Found: C, 70.56; H, 4.58; N, 9.18.
3-Phenyl-5-(4-hydroxy-2-oxo-2H-1-benzopyran-3-yl)-6-methyl-
1,4,5-trihydro-pyrazol (4b).
4-Hydroxy-2-oxo-3-(3'oxo-3'-phenylprop-1'-enyl)-2H-1-ben-
zopyran (3a).
Compound 4b was obtained in 54% yield; mp: 219-220 °C; IR
Compound 3a was obtained in 78% yield; mp: 239-240 °C;IR
(KBr): 3421 (-OH), 1722 (>C=O), 1672, 1578, 1156 cm ; H
(KBr): 3432 (-OH, -NH), 2924 (-CH stretching), 1725 (>C=O),
-1
1
-1
1
1614, 1332 cm ; H NMR (DMSO-d ): δ 2.40 (s, 3H, CH ), δ
6
3
NMR (CDCl ): δ 6.90 (d, 1H,J=9Hz, C '), δ 7.20-8.00 (m, 9H,
2.65 (d, 2H, C -H), δ 4.60 (t, 1H, C -H), δ 7.00-7.60 (m, 8H, aro-
3
2
4
5
aromatic-H), δ 7.80 (d, 1H,J=9Hz, C ') and δ 9.80 (s, 1H, -OH,
matic-H), δ 7.80 (broad, 1H, NH, D O exchangeable) and δ 9.80
1
2
D O exchangeable).
(s, 1H, OH, D O exchangeable).
2
2
Anal. Calcd. For C
H O : C, 73.97; H, 4.11. Found: C,
18 12 4
Anal. Calcd. For C
H
N O : C, 71.25; H, 5; N, 8.75. Found:
19 16 2 3
73.93; H, 4.16.
C, 71.22; H, 4.49; N, 8.77.
4-Hydroxy-6-methyl-2-oxo-3-(3'oxo-3'-phenylprop-1'-enyl)-2H-
1-benzopyran (3b).
3-Phenyl-5-(4-hydroxy-2-oxo-2H-1-benzopyran-3-yl)-7-methyl-
1,4,5-trihydro-pyrazol (4c).
Compound 3b was obtained in 77% yield; mp: 142-143 °C; IR
Compound 4c was obtained in 53% yield; mp: >266 °C; IR
(KBr): 3422 (-OH), 2924(-CH stretching), 1722 (>C=O), 1680,
(KBr): 3416(-OH, -NH), 2925 (-CH stretching), 1715(>C=O),
-1
1
-1
1
1621, 1432 cm ; H NMR (CDCl ): δ 2.40 (s, 3H, CH ), δ 6.80
1615, 1455 cm ; H NMR (DMSO-d ): δ 2.40 (s, 3H, CH ), δ
3
3
6
3
(d, 1H,J=9Hz, C '), δ 7.20-7.80 (m, 8H, aromatic-H), δ 8.00-8.20
2.56 (d, 2H, C -H), δ 4.40 (t, 1H, C -H), δ 7.10-7.90 (m, 8H, aro-
2
4
5
(d, 1H,J=9Hz, C ') and δ 9.80 (s, 1H, -OH, D O exchangeable).
matic-H), δ 8.00 (broad, 1H, NH, D O exchangeable) and δ 9.90
1
2
2
The dibromo derivative of 3b: mp: 184 °C .IR (KBr): 3424(-OH),
2925(-CH stretching), 1723(>C=O), 1618, 1447, 1240 cm .
(s, 1H, OH, D O exchangeable).
2
-1
Anal. Calcd. For C
H
N O : C, 71.25; H, 5; N, 8.75. Found:
19 16 2 3
Anal. Calcd. For C
H O : C, 74.51; H, 4.58. Found: C,
C, 71.26; H, 4.48; N, 8.76.
19 14 4
74.48; H, 4.60.
3-Phenyl-5-(4-hydroxy-2-oxo-2H-1-benzopyran-3-yl)-8-methyl-
1,4,5-trihydro-pyrazol (4d).
4-Hydroxy-7-methyl-2-oxo-3-(3'oxo-3'-phenylprop-1'-enyl)-2H-
1-benzopyran (3c).
Compound 4d was obtained in 55% yield; mp: 209-210 °C; IR
Compound 3c was obtained in 79% yield; mp: 129-130 °C; IR
(KBr): 3393 (-OH, -NH), 2921(-CH stretching), 1710(>C=O),
-1
1
(KBr): 3371 (-OH), 2925 (-CH stretching), 1714 (>C=O), 1619,
1599, 1426 cm ; H NMR (DMSO-d ): δ 2.30 (s, 3H, CH ), δ
6
3
-1
1
1455, 1241 cm ; H NMR (CDCl ): δ 2.40 (s, 3H, CH ), δ 6.70
2.80 (d, 2H, C -H), δ 4.20 (t, 1H, C -H), δ 7.20-7.80 (m, 8H, aro-
3
3
4
5
(d, 1H, J=9Hz, C '), δ 7.20-7.70 (m, 8H, aromatic-H), δ 7.90 (d,
matic-H), δ 7.90 (broad, 1H, NH, D O exchangeable) and δ 9.80
2
2
1H,J=9Hz, C ') and δ 9.90 (s, 1H, -OH, D O exchangeable).
(s, 1H, OH, D O exchangeable).
1
2
2
Anal. Calcd. For C
H
O : C, 74.51; H, 4.58. Found: C,
Anal. Calcd. For C
H
N O : C, 71.25; H, 5; N, 8.75. Found:
19 14
4
19 16 2 3
74.47; H, 4.62.
C, 71.24; H, 5.1; N, 8.77.
4-Hydroxy-8-methyl-2-oxo-3-(3'oxo-3'-phenylprop-1'-enyl)-2H-
1-benzopyran (3d).
4-Hydroxy-2-oxo-2H-1-benzopyran-3-aldehyde-semicarbazones
(5a-d).
Compound 3d was obtained in 76% yield; mp: 159-160 °C; IR
An ethanolic solution of 2 (0.01 mol) was dissolved in ethanol
(20 ml) to this a dilute ethanolic solution (1:1) of semicarbazide
hydrochloride (0.01 mol) was added. It was then acidified with
acetic acid (0.5 ml) and stirred for 6 hours at room temperature.
On cooling a solid was obtained that was collected by filtration
washed with water and recrystallized from ethanol.
(KBr): 3417 (-OH), 2925 (-CH stretching), 1717(>C=O), 1610,
-1 1
1430, 1219 cm ; H NMR (CDCl ): δ 2.35 (s, 3H, CH ), δ 6.80
3
3
(d, 1H,J=9Hz, C '), δ 7.10-7.70 (m, 8H, aromatic-H), δ 8.00 (d,
2
1H,J=9Hz, C ') and δ 9.80 (s, 1H, -OH, D O exchangeable).
1
2
Anal. Calcd. For C
H
O : C, 74.51; H, 4.58. Found: C,
19 14
4
74.52; H, 4.56.
4-Hydroxy-2-oxo-2H-1-benzopyran-3-aldehyde-semicarbazone
(5a).
3-Phenyl-5-(4-hydroxy-2-oxo-2H-1-benzopyran-3-yl)-1,4,5-tri-
hydro-pyrazols (4a-d).
Compound 5a was obtained in 73%; mp: >270 °C; IR (KBr):
To a solution of 3 (0.03 mol) in methanol (20 ml) and an excess
of hydrazine hydrate (8 ml) was added 0.5 ml acetic acid. The
3449 (-OH, -NH -NH), 1722 (>C=O), 1661, 1613, 1568, 1388
2,
-1
1
cm ; H NMR (CDCl ): δ 5.30 (s, 1H, CH=N), δ 7.00-7.60 (m,
3

380
V. V. Mulwad and J. M. Shirodkar
Vol. 40
-1
1
4H, aromatic-H), δ7.7 (s, 2H, NH , D O exchangeable), δ 7.85
1686, 1623, 1577, 1375cm ; H NMR (CDCl ): δ 2.40 (s, 3H,
3
2
2
(s, 1H, -NH, D O exchangeable) and δ 9.70 (s, 1H, -OH, D O
CH ), δ 7.10-7.60 (m, 3H, aromatic-H), δ 7.30 (s, 1H, -NH, D O
2
2
3
2
exchangeable).
Anal. Calcd. For C
exchangeable), δ 7.90 (s, 1H, -NH, D O exchangeable) and δ
2
H
N O : C, 53.44; H, 3.67; N, 17.
9.80 (s, 1H, -OH, D O exchangeable).
11
9
3
4
2
Found: C, 53.42; H, 3.69; N, 17.12.
Anal. Calcd. For C H N O : C, 55.60; H, 3.47; N, 16.22.
12 9 3 4
Found: C, 55.58; H, 3.49; N, 16.20.
4-Hydroxy-6-methyl-2-oxo-2H-1-benzopyran-3-aldehyde-semi-
carbazone (5b).
5-(4-Hydroxy-2-oxo-7-methyl-2H-1-benzopyran-3-yl)-2,4-dihy-
dro[1,2,4]triazol-3-one (6c).
Compound 5b was obtained in 75% yield; mp: >275 °C; IR
(KBr): 3432(-OH, -NH -NH), 2925 (-CH stretching), 1723
Compound 6c was obtained in 63% yield is 63%; mp: >269
2,
-1
(>C=O), 1668, 1610, 1373 cm .
°C; IR (KBr): 3391 (-OH, -NH), 2923 (CH, Stretching),
1
-1 1
H NMR (CDCl ): δ 2.40 (s, 3H, CH ), δ 5.20 (s, 1H, CH=N),
1723(>C=O), 1682, 1621, 1567, 1350 cm ; H NMR (CDCl ): δ
3
3
3
δ 7.15-7.60 (m, 3H, aromatic-H), δ 7.80 (s, 2H, NH , D O
2.30 (s, 3H, CH ), δ 7.10-7.80 (m, 3H, aromatic-H), δ 7.40 (s,
2
2
3
exchangeable), δ 8.00 (s, 1H, -NH, D O exchangeable) and δ
1H, -NH, D O exchangeable), δ 8.20 (s, 1H, -NH, D O
2
2
2
9.80 (s, 1H, -OH, D O exchangeable).
exchangeable) and δ 9.90 (s, 1H, -OH, D O exchangeable).
2
2
Anal. Calcd. For C
H
N O : C, 55.17; H, 4.21; N, 16.09.
Anal. Calcd. For C H N O : C, 55.60; H, 3.47; N, 16.22.
12 11 3 4
12
9 3 4
Found: C, 55.15; H, 4.25; N, 16.
Found: C, 55.57; H, 3.50; N, 16.21.
4-Hydroxy-7-methyl-2-oxo-2H-1-benzopyran-3-aldehyde-semi-
carbazone (5c).
5-(4-Hydroxy-2-oxo-8-methyl-2H-1-benzopyran-3-yl)-2,4-
dihydro[1,2,4]triazol-3-one (6d).
Compound 5c was obtained in 72% yield; mp: 192-193 °C. IR
Compound 6d was obtained in 65% yield; mp: 280 °C; IR
(KBr): 3424(-OH, -NH -NH), 2928 (CH, stretching), 1723
(KBr): 3382 (-OH, -NH), 2925(-CH stretching), 1721(>C=O),
2,
-1
1
-1 1
(>C=O), 1669, 1611, 1376 cm ; H NMR (CDCl ): δ 2.20 (s,
1685, 1611, 1440 cm ; H NMR (CDCl ): δ 2.30 (s, 3H, CH ), δ
3
3
3
3H, CH ), δ 5.10 (s, 1H, CH=N), δ 7.20-7.60 (m, 3H, aromatic-
7.20-7.80 (m, 3H, aromatic-H), δ 7.40 (s, 1H, -NH, D O
3
2
H), δ 7.75 (s, 2H, NH , D O exchangeable), δ 7.95 (s, 1H, -NH,
exchangeable), δ 8.20 (s, 1H, -NH, D O exchangeable) and δ
2
2
2
D O exchangeable) and δ 9.80 (s, 1H, -OH, D O exchangeable).
9.80 (s, 1H, -OH, D O exchangeable).
2
2
2
Anal. Calcd. For C
H
N O : C, 55.17; H, 4.21; N, 16.09.
Anal. Calcd. For C H N O : C, 55.60; H, 3.47; N, 16.22.
12 11
3 4
12
9 3 4
Found: C, 55.16; H, 4.26; N, 16.11.
Found: C, 55.57; H, 3.50; N, 16.20.
4-Hydroxy-8-methyl-2-oxo-2H-1-benzopyran-3-aldehyde-semi-
carbazone (5d).
Acknowledgment.
We are thankful to Mr. S. V. Chiplunkar, U.D.C.T. for elemen-
tal analysis, Director R. S. I. C., I. I. T. and T. I. F. R. Mumbai for
Compound 5d was obtained in 74% yield; mp: 214-215 °C; IR
(KBr): 3434(-OH, -NH -NH), 2925 (CH, stretching), 1716
2,
1
H NMR spectral analysis, Haffkine Institute for studies in
-1 1
(>C=O), 1668, 1609,1355 cm ; H NMR (CDCl ): δ 2.30 (s, 3H,
3
microbial activities and to government of Maharashtra and
LADY TATA MEMORIABLE TRUST for granting scholarship
CH ), δ 4.80 (s, 1H, CH=N), δ 7.10-7.60 (m, 3H, aromatic-H), δ
3
7.75 (s, 2H, NH , D O exchangeable), δ 7.95 (s, 1H, -NH, D O
2
2
2
exchangeable) and δ 9.80 (s, 1H, -OH, D O exchangeable).
2
REFERENCES AND NOTES
Anal. Calcd. For C
H
N O : C, 55.17; H, 4.21; N, 16.09.
12 11 3 4
Found: C, 55.19; H, 4.22; N, 16.10.
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-1 1
cm ; H NMR (CDCl ): δ 7.15-7.80 (m, 3H, aromatic-H), δ 7.60
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2
2
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2
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11
7 3 4
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Compound 6b was obtained in 65% yield; mp: 239-240 °C; IR
(KBr): 3391 (-OH, -NH), 2925(-CH Stretching), 1724 (>C=O),

Mar-Apr 2003
Synthesis Anti-fungal and Anti-bacterial Screening of 3-Phenyl-1,4,5-trihydro-pyrazol
381
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