Sydnones as masked hydrazines for the synthesis of 4-arylazo-1,2-dihydro- pyrazol-3-one derivatives

Article abstract of DOI:10.1080/00397910500182333

A simple and convenient one-pot synthesis of 4-(4-chlorophenylazo)-5- methyl-2-aryl-1,2-dihydro-pyrazol-3-ones (4a-j) has been carried out from 3-arylsydnones (3a-j) by reaction with 2-(4-chlorophenyl)-hydrazono-3-oxo- butyric acid ethyl ester (2b). The 3-arylsydnones are used as masked hydrazines in this reaction. Similarly, the 4-arylazo-2-(7-hydroxy-4-methyl-2-oxo-2H- chromen-8-ylmethyl)-5-methyl-1,2-dihydro-pyrazol-3-ones (7a-j) were synthesized from 3-[(7-acetoxy-4-methyl-8-methylene)coumaryl]sydnone (5). All the newly synthesized compounds exhibited antimicrobial activity greater than the reference drugs used. Copyright Taylor & Francis, Inc.

Full text of DOI:10.1080/00397910500182333

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Sydnones as Masked
Hydrazines for the Synthesis of
4‐Arylazo‐1,2‐dihydro‐pyrazol‐3‐on
Derivatives
Prashant S. Shinge a , Prashant R. Latthe a & Bharati
V. Badami a
a P.G. Department of Chemistry, Karnatak University,
Dharwad, India
Published online: 18 Aug 2006.
To cite this article: Prashant S. Shinge , Prashant R. Latthe & Bharati
V. Badami (2005) Sydnones as Masked Hydrazines for the Synthesis of
4‐Arylazo‐1,2‐dihydro‐pyrazol‐3‐one Derivatives, Synthetic Communications: An
International Journal for Rapid Communication of Synthetic Organic Chemistry, 35:16,
2169-2176
To link to this article: http://dx.doi.org/10.1080/00397910500182333
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Synthetic Communicationsw, 35: 2169–2176, 2005
Copyright # Taylor & Francis, Inc.
ISSN 0039-7911 print/1532-2432 online
DOI: 10.1080/00397910500182333
Sydnones as Masked Hydrazines for the
Synthesis of 4-Arylazo-1,2-dihydro-pyrazol-
3-one Derivatives
Prashant S. Shinge, Prashant R. Latthe,
and Bharati V. Badami
P.G. Department of Chemistry, Karnatak University, Dharwad, India
Abstract: A simple and convenient one-pot synthesis of 4-(4-chlorophenylazo)-5-
methyl-2-aryl-1,2-dihydro-pyrazol-3-ones (4a–j) has been carried out from 3-arylsyd-
nones (3a–j) by reaction with 2-(4-chlorophenyl)-hydrazono-3-oxo-butyric acid ethyl
ester (2b). The 3-arylsydnones are used as masked hydrazines in this reaction.
Similarly, the 4-arylazo-2-(7-hydroxy-4-methyl-2-oxo-2H-chromen-8-ylmethyl)-5-
methyl-1,2-dihydro-pyrazol-3-ones (7a–j) were synthesized from 3-[(7-acetoxy-4-
methyl-8-methylene)coumaryl]sydnone (5). All the newly synthesized compounds
exhibited antimicrobial activity greater than the reference drugs used.
Keywords: 3-arylsydnones, 4-arylazo-pyrazolones
The synthetic utility of 3-arylsydnones (3a–j) for the preparation of many bio-
logically active heterocycles has been reported from this laboratory during the
past two decades.[1–5] In this article, we describe further utilization of this
strategy for the preparation of some new 4-(4-chlorophenylazo)-5-methyl-2-
aryl-1,2-dihydro-pyrazol-3-ones (4a–j) and 4-arylazo-2-(7-hydroxy-4-methyl-
2-oxo-2H-chromen-8-ylmethyl)-5-methyl-1,2-dihydro-pyrazol-3-ones (7a–j).
The aim of this work came from the observation that such azo pyrazole/
pyrazolone rings are used for their diverse applications, namely for the pro-
Received in India April 23, 2005
Address correspondence to Bharati V. Badami, P.G. Department of Chemistry,
Karnatak University, Dharwad 580 003, India. E-mail: bbadami@rediffmail.com
2169

2170
P. S. Shinge, P. R. Latthe, and B. V. Badami
duction of yellow shades on cotton, silk, wool, and polyester fibers.[6] The
pyrazoles are found to be active against leukaemia in mice.[7] Azopyrazoles[8]
have been screened for their anti-HIV, antibacterial, antitubercular, fungicidal,
and anticancer activities. The pyrazolone azodyes have been used in dyeing silk
and nylon fibres[9] and also in an optical recording medium for write-once, read-
many discs.[10] These observations prompted us to synthesize some new aryl
and coumaryl azopyrazole derivatives.
Sydnones undergo hydrolysis with HCl to give substituted hydrazines,[11]
and this has been recommended as a general and convenient method of
obtaining mono-substituted hydrazines, which are inaccessible or accessible
with difficulty from primary amines by usual methods. Using this property
of sydnones, many such aryl hydrazines have been isolated from the cor-
responding 3-arylsydnones in our laboratory.[1] Using the 3-arylsydnones
as masked hydrazines, we have now synthesized the title compounds—
4-(4-chlorophenylazo)-5-methyl-2-aryl-1,2-dihydro-pyrazol-3-ones (4a–j) by
a one-pot reaction of 3-arylsydnones (3a–j) with 2-(4-chlorophenyl)-
hydrazono-3-oxo-butyric acid ethyl ester (2b). We have prepared the only
p-chloro derivatives, because the chloro-substituted compounds are known
to possess antifungal activity. We were also interested in one of the sydnone—
3-[(7-acetoxy-4-methyl-8-methylene)coumaryl]sydnone (5)—prepared by our
earlier colleagues.[12] We were interested in obtaining the corresponding
8-hydrazinomethyl-7-hydroxy-4-methyl-chromen-2-one (6) by hydrolysis of
the previous compound. However, unsuccessful attempts were made to
isolate the coumarin-substituted hydrazine (6). Hence, we thought of trapping
this hydrazine (6) by reaction with compounds (2a–j). The isolation of the
compounds 4-arylazo-2-(7-hydroxy-4-methyl-2-oxo-2H-chromen-8-ylmethyl)-
5-methyl-1,2-dihydro-pyrazol-3-ones (7a–j) (Scheme 1) was evidence for
the formation of this hydrazine (6) in situ. These compounds were character-
ized on the basis of their spectral and analytical data.
The IR spectra (KBr) of the compounds (4a–j) showed band at
3376 cm21 as a result of pyrazolone nNH. The band at 1703 cm21 was due
1
to pyrazolone nC¼O. The H NMR (300 MHz) (CDCl3) spectra of all these
compounds showed singlet at d 2.33 because of methyl protons on the pyra-
zolone ring. The aromatic protons resonated in the region d 7.9–7.1. The
broad signal at d 13.5 was assigned to pyrazolone NH (D2O exchanged).
The IR spectra of compounds (7a–j) showed broad band at ꢀ3427 cm21
because of phenolic nOH and pyrazolone nNH. The lactone nC¼O appeared at
1
1727 cm21 and the pyrazolone nC¼O at 1705 cm21. The H NMR spectra
showed two singlets at d 2.28 and 2.40 because of methyl protons on
coumarin and pyrazolone rings respectively. The singlet at d 5.24 was
assigned to methylene protons and the singlet at d 6.1 was due to 3-H of the
coumarin ring. The two doublets at d 7.52 and d 6.98 were assigned to C-6
and C-5 protons on the coumarin ring. The aromatic protons resonated in
the region d 7.42–d 7.37. The singlet at d 9.84 because of the C-7 OH
proton of the coumarin ring and a broad peak at d 13.2 because of –NH of

Sydnones as Masked Hydrazines
2171
Scheme 1.
the pyrazolone ring were both D2O exchanged. A mass spectrum of a typical
compound, that is, 4-chlorophenyl derivative (7b), showed the molecular ion
peak at m/z 424 and 426 (3 : 1), which is also the molecular weight of the
compound.
The preliminary antimicrobial testing has been carried out by the cup-
plate method. The antimicrobial activity was done against two pathogenic
bacteria, Escherichia coli (Gram 2ve) and Micrococcus luteus (Gram þve),
and Asperigillus niger and Pencillium notatum as the fungal strains. The
reference drugs used were norfloxacin and Griseofuvin respectively.
Compounds (4b–d and i) with halogen and methyl substitution on the
phenyl ring showed moderate activity against both the bacteria whereas all
the compounds (4a–j) exhibited antifungal activity greater than the
reference drug against A. niger. Among the coumarin derivatives (7a–j),
only the methyl-substituted compounds (7d, g, and j) exhibited moderate
activity against both the bacteria, while the halogen substitution on the
phenyl ring (7b, c, f, and i) enhanced the activity (almost one-and-a-half

2172
P. S. Shinge, P. R. Latthe, and B. V. Badami
times greater) than the reference drug against the A. niger only. From this pre-
liminary antimicrobial activity, we came to the conclusion that the halogen
and methyl substitution on the phenyl ring attached to azo group enhanced
the activity only against Asperigillus niger.
EXPERIMENTAL
Melting points were determined in an open capillary tube and are uncorrected.
The IR spectra were recorded on Nicolet Impact 410 FT IR spectrophotometer
using KBr pellets. 1H NMR was recorded on Bruker 300-MHz FT NMR spec-
trometer in CDCl3 with TMS as an internal standard. Mass spectra were
recorded on a M.I. ver. 14 on UIC 002002. Elemental analysis was carried
out using Heraus CHN rapid analyzer.
4-(4-Chlorophenylazo)-5-methyl-2-aryl-1,2-dihydro-pyrazol-3-ones
(4a–j)
A
mixture of 3-arylsydnones (3a–j) (0.01 mol), 2-(4-chlorophenyl)-
hydrazono-3-oxo-butyric acid ethyl ester (2b) and conc. HCl (10 ml) was
heated under reflux for about 4 h. The reaction mixture was then poured in
ice water and neutralized with ammonia. The orange solid obtained was
purified by column chromatography using ethyl acetate as eluent.
IR spectra (KBr) of (4a–j) showed the broad absorption characteristic of
pyrazolone nNH around (3376 cm21) and nC¼O of pyrazolone absorptions
around (1705 cm21).
4a: Yield: 80%, mp 214–2168C. 1H NMR (CDCl3): d 2.33 (s, 3H, pyra-
zolone CH3), 7.9 (d, 2H, Ar-H), 7.4 (d, 2H, Ar-H), 7.3–7.1 (m, 5H, Ar-H),
13.5 (br, 1H, pyrazolone NH, D2O exchangeable). Anal. calcd. for
C16H13ClN4O: C, 61.53; H, 4.16; N, 17.94. Found: C, 61.50; H, 4.12; N,
17.90.
4b: Yield: 85%, mp 232–2348C. 1H NMR (CDCl3): d 2.35 (s, 3H, pyra-
zolone CH3), 7.8 (d, 2H, Ar-H), 7.53 (d, 2H, Ar-H), 7.42 (d, 2H, Ar-H), 7.18
(d, 2H, Ar-H), 13.39 (br, 1H, pyrazolone NH, D2O exchangeable). Anal.
calcd. for C16H12Cl2N4O: C, 55.49; H, 3.46; N, 16.18. Found: C, 55.40; H,
3.43; N, 16.13.
4c: Yield: 78%, mp 225–2278C. 1H NMR (CDCl3): d 2.36 (s, 3H, pyra-
zolone CH3), 7.83 (d, 2H, Ar-H), 7.51 (d, 2H, Ar-H), 7.40 (d, 2H, Ar-H), 7.19
(d, 2H, Ar-H), 13.36 (br, 1H, pyrazolone NH, D2O exchangeable). Anal.
calcd. for C16H12BrClN4O: C, 49.10; H, 3.07; N, 14.32. Found: C, 49.05;
H, 3.02; N, 14.30.
4d: Yield: 81%, mp 184–1868C. 1H NMR (CDCl3): d 2.36 (s, 3H, pyra-
zolone CH3), 2.28 (s, 3H, Ar-CH3), 7.83 (d, 2H, Ar-H), 7.51 (d, 2H, Ar-H),
7.40 (d, 2H, Ar-H), 7.19 (d, 2H, Ar-H), 13.36 (br, 1H, pyrazolone NH, D2O

Sydnones as Masked Hydrazines
2173
exchangeable). Anal. calcd. for C17H15ClN4O: C, 62.57; H, 4.60; N, 17.17.
Found: C, 62.51; H, 4.54; N, 17.13.
4e: Yield: 80%, mp 192–1948C. 1H NMR (CDCl3): d 2.35 (s, 3H, pyra-
zolone CH3), 3.8 (s, 3H, Ar-OCH3), 7.84 (d, 2H, Ar-H), 7.53 (d, 2H, Ar-H),
7.34 (d, 2H, Ar-H), 7.21 (d, 2H, Ar-H), 13.42 (br, 1H, pyrazolone NH, D2O
exchangeable). Anal. calcd. for C17H15ClN4O2: C, 59.65; H, 4.38; N, 16.37.
Found: C, 59.60; H, 4.33; N, 16.33.
4f: Yield: 78%, mp 178–1808C. 1H NMR (CDCl3): d 2.35 (s, 3H, pyra-
zolone CH3), 7.8 (d, 2H, Ar-H), 7.53 (d, 2H, Ar-H), 7.42 (s, 1H, Ar-H), 7.18
(m, 3H, Ar-H), 13.39 (br, 1H, pyrazolone NH, D2O exchangeable). Anal.
calcd. for C16H12Cl2N4O: C, 55.49; H, 3.46; N, 16.18. Found: C, 55.44; H,
3.41; N, 16.12.
4g: Yield: 74%, mp 172–1748C. 1H NMR (CDCl3): d 2.38 (s, 3H, pyra-
zolone CH3), 2.27 (s, 3H, Ar-CH3), 7.82 (d, 2H, Ar-H), 7.51 (d, 2H, Ar-H),
7.39 (s, 1H, Ar-H), 7.13 (m, 3H, Ar-H), 13.32 (br, 1H, pyrazolone NH, D2O
exchangeable). Anal. calcd. for C17H15ClN4O: C, 62.57; H, 4.60; N, 17.17.
Found: C, 62.50; H, 4.56; N, 17.15.
4h: Yield: 73%, mp 179–1808C. 1H NMR (CDCl3): d 2.35 (s, 3H, pyra-
zolone CH3), 3.83 (s, 3H, Ar-OCH3), 7.84 (d, 2H, Ar-H), 7.53 (d, 2H, Ar-H),
7.34 (s, 1H, Ar-H), 7.21 (m, 3H, Ar-H), 13.42 (br, 1H, pyrazolone NH, D2O
exchangeable). Anal. calcd. for C17H15ClN4O2: C, 59.65; H, 4.38; N, 16.37.
Found: C, 59.62; H, 4.33; N, 16.32.
4i: Yield: 84%, mp 238–2408C. 1H NMR (CDCl3): d 2.36 (s, 3H, pyra-
zolone CH3), 2.28 (s, 3H, Ar-CH3), 7.83 (d, 2H, Ar-H), 7.51 (d, 2H, Ar-H),
7.40 (d, 1H, Ar-H), 7.19 (d, 1H, Ar-H), 7.39 (s, 1H, Ar-H), 13.36 (br, 1H, pyr-
azolone NH, D2O exchangeable). Anal. calcd. for C17H14Cl2N4O: C, 56.66; H,
3.89; N, 15.55. Found: C, 56.61; H, 3.85; N, 15.50.
4j: Yield: 82%, mp 219–2218C. 1H NMR (CDCl3): d 2.36 (s, 3H, pyra-
zolone CH3), 2.28 (s, 3H, Ar-CH3), 7.83 (d, 2H, Ar-H), 7.51 (d, 2H, Ar-H),
7.40 (d, 1H, Ar-H), 7.19 (d, 1H, Ar-H), 7.39 (s, 1H, Ar-H), 13.36 (br, 1H, pyr-
azolone NH, D2O exchangeable). Anal. calcd. for C17H14ClN5O3: C, 54.98; H,
3.77; N, 18.86. Found: C, 54.90; H, 3.72; N, 18.81.
4-Arylazo-2-(7-hydroxy-4-methyl-2-oxo-2H-chromen-8-ylmethyl)-
5-methyl-1,2-dihydro-pyrazol-3-ones (7a–j)
These compounds were prepared by the same procedure as previously
mentioned for compounds (4a–j). The compounds were also obtained as
orange solids. IR spectra (KBr) of (7a–j) showed broad absorption character-
istic of pyrazolone nNH and phenolic nOH (3427–2924 cm21) and two nC¼O
absorptions around 1722 and 1705 cm21 for coumarin and pyrazolone respect-
ively.
7a: Yield: 78%, mp 242–2448C. 1H NMR (CDCl3): d 2.28 (s, 3H, 4-CH3
of coumarin), 2.40 (s, 3H, pyrazolone CH3), 5.2 (s, 2H, methylene protons),

2174
P. S. Shinge, P. R. Latthe, and B. V. Badami
6.1 (s, 1H, C-3H of coumarin), 6.98 (d, 1H, C-5H of coumarin), 7.5 (d, 1H,
C-6H of coumarin), 7.42–7.2 (m, 5H, Ar-H), 9.8 (s, 1H, phenolic OH, D2O
exchangeable), 13.1 (br, 1H, pyrazolone NH, D2O exchangeable). Anal.
calcd. for C21H18N4O4: C, 64.61; H, 4.61; N, 14.36. Found: C, 64.56;
H, 4.58; N, 14.32.
7b: Yield: 85%, mp 251–2538C. 1H NMR (CDCl3): d 2.27 (s, 3H, 4-CH3
of coumarin), 2.38 (s, 3H, pyrazolone CH3), 5.22 (s, 2H, methylene protons),
6.13 (s, 1H, C-3H of coumarin), 6.98 (d, 1H, C-5H of coumarin), 7.6 (d, 1H,
C-6H of coumarin), 7.52 (d, 2H, Ar-H), 7.2 (d, 2H, Ar-H), 9.8 (s, 1H, phenolic
OH, D2O exchangeable), 13.15 (br, 1H, pyrazolone NH, D2O exchangeable).
Anal. calcd. for C21H17ClN4O4: C, 59.43; H, 4.00; N, 13.20. Found: C, 59.40;
H, 3.96; N, 13.16.
7c: Yield: 88%, mp 255–2578C. 1H NMR (CDCl3): d 2.27 (s, 3H, 4-CH3
of coumarin), 2.38 (s, 3H, pyrazolone CH3), 5.22 (s, 2H, methylene protons),
6.13 (s, 1H, C-3H of coumarin), 6.98 (d, 1H, C-5H of coumarin), 7.6 (d, 1H,
C-6H of coumarin), 7.52 (d, 2H, Ar-H), 7.2 (d, 2H, Ar-H), 9.8 (s, 1H, phenolic
OH, D2O exchangeable), 13.15 (br, 1H, pyrazolone NH, D2O exchangeable).
Anal. calcd. for C21H17BrN4O4: C, 53.73; H, 3.62; N, 11.94. Found: C, 53.69;
H, 3.58; N, 11.92.
7d: Yield: 80%, mp 239–2418C. 1H NMR (CDCl3): d 2.27 (s, 3H, 4-CH3
of coumarin), 2.36 (s, 3H, Ar-CH3), 2.38 (s, 3H, pyrazolone CH3), 5.21 (s, 2H,
methylene protons), 6.15 (s, 1H, C-3H of coumarin), 6.99 (d, 1H, C-5H of
coumarin), 7.7 (d, 1H, C-6H of coumarin), 7.52 (d, 2H, Ar-H), 7.2 (d, 2H,
Ar-H), 9.9 (s, 1H, phenolic OH, D2O exchangeable), 13.21 (br, 1H, pyrazo-
lone NH, D2O exchangeable). Anal. calcd. for C22H20N4O4: C, 65.34; H,
4.95; N, 13.84. Found: C, 65.28; H, 4.92; N, 13.80.
7e: Yield: 76%, mp 244–2468C. 1H NMR (CDCl3): d 2.27 (s, 3H, 4-CH3
of coumarin), 3.8 (s, 3H, Ar-OCH3), 2.38 (s, 3H, pyrazolone CH3), 5.21 (s, 2H,
methylene protons), 6.15 (s, 1H, C-3H of coumarin), 6.99 (d, 1H, C-5H of
coumarin), 7.7 (d, 1H, C-6H of coumarin), 7.52 (d, 2H, Ar-H), 7.2 (d, 2H,
Ar-H), 9.9 (s, 1H, phenolic OH, D2O exchangeable), 13.21 (br, 1H, pyrazo-
lone NH, D2O exchangeable). Anal. calcd. for C22H20N4O5: C, 62.85; H,
4.76; N, 13.33. Found: C, 62.80; H, 4.73; N, 13.31.
7f: Yield: 79%, mp 209–2118C. 1H NMR (CDCl3): d 2.27 (s, 3H, 4-CH3
of coumarin), 2.38 (s, 3H, pyrazolone CH3), 5.22 (s, 2H, methylene protons),
6.13 (s, 1H, C-3H of coumarin), 6.98 (d, 1H, C-5H of coumarin), 7.6 (d, 1H,
C-6H of coumarin), 7.52 (s, 1H, Ar-H), 7.2 (m, 3H, Ar-H), 9.8 (s, 1H, phenolic
OH, D2O exchangeable), 13.15 (br, 1H, pyrazolone NH, D2O exchangeable).
Anal. calcd. for C21H17ClN4O4: C, 59.43; H, 4.00; N, 13.20. Found: C, 59.40;
H, 3.96; N, 13.15.
7g: Yield: 73%, mp 204–2068C. 1H NMR (CDCl3): d 2.27 (s, 3H, 4-CH3
of coumarin), 2.36 (s, 3H, Ar-CH3), 2.38 (s, 3H, pyrazolone CH3), 5.21 (s, 2H,
methylene protons), 6.15 (s, 1H, C-3H of coumarin), 6.99 (d, 1H, C-5H of
coumarin), 7.7 (d, 1H, C-6H of coumarin), 7.42 (s, 1H, Ar-H), 7.25 (m, 3H,
Ar-H), 9.73 (s, 1H, phenolic OH, D2O exchangeable), 13.19 (br, 1H, pyrazo-

Sydnones as Masked Hydrazines
2175
lone NH, D2O exchangeable). Anal. calcd. for C22H20N4O4: C, 65.34; H, 4.95;
N, 13.84. Found: C, 65.29; H, 4.89; N, 13.79.
7h: Yield: 74%, mp 223–2258C. 1H NMR (CDCl3): d 2.25 (s, 3H, 4-CH3
of coumarin), 3.83 (s, 3H, Ar-OCH3), 2.42 (s, 3H, pyrazolone CH3), 5.24
(s, 2H, methylene protons), 6.19 (s, 1H, C-3H of coumarin), 6.94 (d, 1H,
C-5H of coumarin), 7.69 (d, 1H, C-6H of coumarin), 7.62 (s, 1H, Ar-H),
7.35 (m, 3H, Ar-H), 10.1 (s, 1H, phenolic OH, D2O exchangeable), 13.21
(br, 1H, pyrazolone NH, D2O exchangeable). Anal. calcd. for C22H20N4O5:
C, 62.85; H, 4.76; N, 13.33. Found: C, 62.80; H, 4.73; N, 13.28.
7i: Yield: 77%, mp 235–2378C. 1H NMR (CDCl3): d 2.27 (s, 3H, 4-CH3
of coumarin), 2.36 (s, 3H, Ar-CH3), 2.41 (s, 3H, pyrazolone CH3), 5.21 (s, 2H,
methylene protons), 6.15 (s, 1H, C-3H of coumarin), 6.99 (d, 1H, C-5H of
coumarin), 7.7 (d, 1H, C-6H of coumarin), 7.42 (d, 1H, Ar-H), 7.25 (d, 1H,
Ar-H), 7.59 (s, 1H, Ar-H), 9.73 (s, 1H, phenolic OH, D2O exchangeable),
13.19 (br, 1H, pyrazolone NH, D2O exchangeable). Anal. calcd. for
C22H19ClN4O4: C, 60.27; H, 4.33; N, 12.78. Found: C, 60.21; H, 4.30; N,
12.73.
7j: Yield: 83%, mp 265–2678C. 1H NMR (CDCl3): d 2.27 (s, 3H, 4-CH3
of coumarin), 2.36 (s, 3H, Ar-CH3), 2.41 (s, 3H, pyrazolone CH3), 5.21 (s, 2H,
methylene protons), 6.15 (s, 1H, C-3H of coumarin), 6.99 (d, 1H, C-5H of
coumarin), 7.7 (d, 1H, C-6H of coumarin), 7.42 (d, 1H, Ar-H), 7.25 (d, 1H,
Ar-H), 7.59 (s, 1H, Ar-H), 9.73 (s, 1H, phenolic OH, D2O exchangeable),
13.19 (br, 1H, pyrazolone NH, D2O exchangeable). Anal. calcd. for
C22H19N5O6: C, 58.70; H, 4.23; N, 15.59. Found: C, 58.75; H, 4.19; N, 15.50.
ACKNOWLEDGMENTS
We thank G. S. Puranik, retired professor of Organic Chemistry and former
chairman, Department of Chemistry, Karnatak University, Dharwad, India,
for encouragement and suggestions. Authors also thank Sophisticated Instru-
ments Facility (SIF), Indian Institute of Science, Bangalore, and University
Scientific Instrumentation Centre (USIC), Karnatak University, Dharwad,
India, for providing spectral data.
REFERENCES
1. Dambal, D. B.; Badami, B. V.; Puranik, G. S. Indian J. Chem. 1982, 21B,
865–868.
2. Tikare, R. K.; Badami, B. V.; Puranik, G. S. Indian J. Chem. 1983, 22B, 673–677.
3. Badachikar, S. V.; Tikare, R. K.; Puranik, G. S. Indian J. Chem. 1986, 25B,
1079–1080.
4. Mallur, S. G.; Badami, B. V. Il Farmaco 2000, 55, 65–67.
5. Kavali, J. R.; Kotresh, O.; Badami, B. V. J. Chem. Res. Synop. 2003, 5, 275.

2176
P. S. Shinge, P. R. Latthe, and B. V. Badami
6. Jolly, V. S.; Srivastava, A. K.; Singh, S. P.; Tiwari, K. S. J. Ind. Chem. Soc. 1980,
57 (5), 539–541.
7. Sullivan, O.; Conalty, M. L. Proc. R. Ir. Acad. 1980, 8013, 385–394.
8. Dhingra, V.; Bhatawdekar, R.; Agarwal, L.; Jolly, V. S. J. Ind. Chem. Soc. 1991,
68, 672.
9. Naik, R. D.; Desai, K. R. Orient J. Chem. 1998, 14 (1), 161–162.
10. Miyazawa, T.; Kurose, H. Jpn. Kokai. Tokkyo. Kohi. Hiroshi. JP 2001, 158, 862.
11. Ohta, M.; Kato, H. Nonbenzenoid Aromatics; Snyder, J. P., Ed.; Academic Press:
New York, 1969, p. 158.
12. Mallur, S. G. Ph. D. Thesis, Karnatak University, Dharwad, India, 1997
(unpublished work).