A facile regioselective synthesis of novel spiro-thioxanthene and spiro-xanthene-9′,2-[1,3,4]thiadiazole derivatives as potential analgesic and anti-inflammatory agents

Article abstract of DOI:10.1016/j.bmcl.2008.07.042

The 1,3-dipolar cycloaddition of nitrile imines to 9H-thioxanthone-9-thione and 9H-xanthone-9-thione afforded novel spiro-thioxanthene-9′,2-[1,3,4]thiadiazoles 6a-g and spiro-xanthene-9′,2-[1,3,4]thiadiazoles 7a-g in good yields. Some of the newly synthesized compounds were tested for anti-inflammatory and analgesic activities comparable to ibuprofen. Compounds 6a,d,e and 7a,d,e showed significant activity compared to standard drug. The toxicity studies revealed that neither death nor other behavioral or toxicological changes were observed on rats up to a dose as high as 200 mg/kg.

Full text of DOI:10.1016/j.bmcl.2008.07.042

Bioorganic & Medicinal Chemistry Letters 18 (2008) 4538–4543
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
A facile regioselective synthesis of novel spiro-thioxanthene and
spiro-xanthene-90,2-[1,3,4]thiadiazole derivatives as potential analgesic
and anti-inflammatory agents
H. N. Hafez a, M. I. Hegab a, I. S. Ahmed-Farag b, A. B. A. El-Gazzar a,
*
a Photochemistry Department, National Research Centre, 12622 Dokki, Giza, Egypt
b X-Ray Lab., Solid State Physics Dept., National Research Centre, 12622 Dokki, Giza, Egypt
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 29 April 2008
Revised 6 July 2008
Accepted 11 July 2008
Available online 15 July 2008
The 1,3-dipolar cycloaddition of nitrile imines to 9H-thioxanthone-9-thione and 9H-xanthone-9-thione
afforded novel spiro-thioxanthene-90,2-[1,3,4]thiadiazoles 6a-g and spiro-xanthene-90,2-[1,3,4]thiadiaz-
oles 7a-g in good yields. Some of the newly synthesized compounds were tested for anti-inflammatory
and analgesic activities comparable to ibuprofen. Compounds 6a,d,e and 7a,d,e showed significant activ-
ity compared to standard drug. The toxicity studies revealed that neither death nor other behavioral or
toxicological changes were observed on rats up to a dose as high as 200 mg/kg.
Keywords:
Spiro-thioxanthene-
Spiro-xanthene-90,2-[1,3,4]thiadiazole
Single crystal X-ray structural analysis
Anti-inflammatory and analgesic activities
Ó 2008 Elsevier Ltd. All rights reserved.
Recently, we described the synthesis of some novel five-mem-
bered heterocycles via 1,3-dipolar cycloaddition using nitrile imi-
nes as 1,3-dipole. The heterocumulenic cation 2 was found to
undergo cycloaddition to multiple bonds of isocyanates, nitriles
and thiones to furnish pyrazoles 3 and thiadiazoles (X@S) (Scheme
1).1–5 We wondered whether these cycloadditions could be applied
to syntheses of spiro-thioxanthene-90,2-[1,3,4]thiadiazole and xan-
thene derivatives.
1,3-Dipolar cycloaddition is a versatile synthetic strategy for the
constructions of five-membered ring heterocycles.6,7 Also, some of
xanthone-9-thiones and thioxanthone-9-thiones exhibit antiviral,8
local anaesthetic,9 bronchodilator10 and anticonvulsant.11 More-
over, xanthene derivatives are useful pharmaceuticals such as
muscarinic receptor antagonist,12 cancer chemotherapy,13 trypa-
nothione reductase inhibitor,14 chemosensitizers against
chloroquine-resistant Plasmodium falciparum,15 nonpeptidic
inhibitors,16 mG1uR1 enhancer17,18 and CCR1 antagonist.19,20
Moreover, the 1,3,4-thiadiazole ring system exhibit biologically
activity, for example leishmanicidal,21 anticonvulsant.22,23 Thus,
syntheses of xanthene derivatives are of immense interest. Accord-
ing to the literature replacement, of oxygen by sulfur in the xan-
thone core also changed the pharmacological profiles of patented
compounds.24 Here we report the syntheses of various spiro-thio-
xanthene-90,2-[1,3,4]thiadiazole derivatives via the cycloaddition
of numerous nitrile imines 5a–g to 9H-thioxanthene-9-thione
and 9H-xanthene-9-thione 4a,b, the structures of which are con-
firmed by X-ray single crystal structural analysis. Besides, the eval-
uation of anti-inflammatory and analgesic activities of some
products has been studied.
The 1,3-dipolar cycloadditions of the nitrile imines generated in
situ from hydrazonoyl chlorides 5a–g and triethylamine in ben-
zene to thioxanthene-9-thione 4a afforded novel 3,5-disubstituted
spiro-thioxanthene-90,2-[1,3,4]thiadiazoles 6a–g in good yields
(76–88%) under dry conditions (Scheme 2). The mixture of an equi-
molar of 4a, C-phenyl-N-phenyl hydrazonoyl chloride 5a in dry
benzene in presence of triethylamine was refluxed for 3 h led to
the compound 6a. This cycloaddition is chemoselective as it occurs
on only C@S of 4a furnishing exclusively the spiro-thioxanthene-
90,2-[1,3,4]thiadiazole 6a. The mechanism of the reaction may
proceed via two pathways: A: regioselectively, as the electron rich
R
N+ N−
Ar
N
C+
R
Y
N
N−
TEA
R
Ar
Ar
N
Cl
-HCl
H
2
1
N
Ar
R
N
X=Y
X
Y
nitriles, isocyanates, thiones
X
3
* Corresponding author. Tel.: +20 2337318830.
E-mail address: profelgazzar@yahoo.com (A.B.A. El-Gazzar).
Scheme 1.
0960-894X/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmcl.2008.07.042

H. N. Hafez et al. / Bioorg. Med. Chem. Lett. 18 (2008) 4538–4543
4539
S
S
Cl
+
N
H
R
N+
N Ar
+
Triethylamine
dry benzene
C
N
R
Ar
X
X
5a-g
path: A
path: B
4a,b
a, X = S
b, X = O
R
S
Ar
N
N
N
N
S
Ar
R
X
X
6a-g , X = S
7a-g , X = O
8
pp
6,7a; R = Ar = C6H5
6,7e; R = COCH3, Ar = p-C6H4-NO2
6,7f; R = COOC2H5, Ar = p-C6H5
6,7b; R = COCH3, Ar = C6H5
6,7c; R = COCH3, Ar = p-C6H4-Br
6,7d; R = COCH3, Ar = p-C6H4-Cl
6,7g; R = COOC2H5, Ar = p-C6H4-CH3
Scheme 2.
Table 1
nitrogen of the dipole adds to the carbon of thione 4a and only one
regioisomer is obtained exclusively in high yields; B: the electron
rich carbon of the dipole adds to the carbon of thione 4a and fur-
nish the other regioisomer 8 (Scheme 2). The spectroscopic analy-
ses (IR, NMR, MS), beside the X-ray crystallographic study (Fig. 1)
conformed the structure 6a and not structure 8.
The crystallographic data and details of structure determination
of thiadiazole derivative 6a are shown in Table 1. Some selected
bond lengths, bond angles, and torsion angles are given in Table 2.
Also, the cycloaddition of nitrile imine generated in situ from C-
acetyl-N-aryl (phenyl, 4-bromophenyl, 4-chlorophenyl and
4-nitrophenyl) 5b–e and triethylamine to 4a afforded 3-aryl-5-
acetyl-spiro-thioxanthene-90,2-[1,3,4]thiadiazole (6b–e) as only
Crystal data and details of structure determination of 6a
Crystal data
Compound 6a
Empirical formula
Formula weight
Shape/color
Crystal system
Space group
Temperature (K)
Wavelength (Å)
Unit cell determinations a (Å)
b (Å)
C26H18N2 S2
422.572
Cube/yellow
Triclinic
ꢀ
P1
298
0.71073
8.1982 (4)
11.1808 (5)
12.1107 (9)
104.565 (2)
93.377 (2)
106.703 (5)
1018.73 (10)
2
c (Å)
a
(°)
b (°)
c
(°)
Volume (Å3)
Z
Density (calculated) (mg mꢀ3
)
1.378
h range for data collection (°)
2.910–21.967
Index ranges
h
0 ? 8
k
l
ꢀ11 ? 11
ꢀ12 ? 12
2931
Reflections, measured
Independent
2443
Observed
1725
Data/restraints/parameters
Goodness-of-fit
R indices (all data), R
wR
1725/0/271
1.036
0.062
0.090
R indeces (I P 3
r(I))
0.049
0.26/ꢀ0.33
Max./min. electron density (eÅꢀ3
)
one pure product in high yields (Scheme 2). The structures of 6b–e
were elucidated using H NMR and MS. The 1H NMR of compound
6c as an example, showed COCH3 at d 2.57 in addition to the aro-
matic protons (12H) around d 6.86–7.57, also the mass spectrum
of 6c showed the prominent ion peak at m/z 467 (M+, 75).
On the other hand, the thiooxo derivative 4a reacted with nitrile
imine generated in situ from C-carboethoxy-N-aryl (phenyl and
4-tolyl) 5f,g as described above to afford the only one product
6f,g, respectively (Scheme 2). The structure of the products 6f,g
were established by elemental analysis and spectral data (IR,
NMR and MS). The 1H NMR spectrum of 6f as an example, showed
Figure 1. Single crystal X-ray diffraction of 6a; the crystallographic numbering
does not reflect the systematic numbering.

4540
H. N. Hafez et al. / Bioorg. Med. Chem. Lett. 18 (2008) 4538–4543
Table 2
The compounds were tested at an oral dose of 70 mg/kg body
weight and were compared with the standard drug ibuprofen at
the same oral dose. The tested compounds showed anti-inflamma-
tory activity ranging from 50% to 86% (Table 4), and the standard
drug ibuprofen showed 92% inhibition after 4 h. The spiro-xan-
thene-90,2-[1,3,4]thiadizole and its thioxanthene 6a, 7a having a
4-nitrophenyl group at position 3 and acetyl group at position 5
showed the maximum activity (84–86%). Also, the spiro com-
pounds which having two phenyl groups at position 3 and 5,
showed high activities (85% and 82%), respectively. Whereas when
the 4-nitro group was replaced by the hydrogen, chlorine and bro-
mine showed good activity around (76–71%), respectively.
The compounds that showed anti-inflammatory activity higher
than 80% were tested for analgesic activity (Table 3). Compounds
6a,d,e and 7a,d,e showed analgesic activity ranging from 57% to
73%, whereas the standard drug ibuprofen showed 84% at a
70 mg/kg oral dose. Among all the tested compounds, the spiro-
thiadiazole derivative having the 4-nitrophenyl group 6e showed
maximum activity (73%). When this group was replaced by the
4-bromophenyl (6d) and phenyl (6a), there was a significant de-
crease in the activity. The rats were observed for possible incidence
of death or other behavioral changes. The toxicity studies revealed
that neither death nor other behavioral or toxicological changes
were observed on rats up to a dose as high as 200 mg/kg.
All melting points were uncorrected and measured using an
Electro-thermal IA 9100 apparatus (Shimadzu, Japan). Microana-
lytical data were performed by Vario, Elementar apparatus (Shima-
dzu). The IR spectra (KBr, cmꢀ1) were recorded on a Perkin-Elmer
1650 spectrometer (USA). 1H NMR spectra were recorded in
DMSO-d6 with tetramethylsilane as an internal standard on a JEOL
EX-270 or on JEOL ECA-500. Mass spectra were recorded on 70 ev
EI Ms-QP 1000 EX (Shimadzu, Japan). The starting materials hyd-
razonoyl chloride (5a–g) were prepared as the same in the litera-
ture.25,26 Reactions were monitored by TLC on silica gel 60 GF254
(0.25 mm).
Selected bond lengths (Å), bond angles (°), and torsion angles (°) for 6a
S1–C6
S1–C17
S2–C14
S2–C18
N3–N4
N3–C6
N4–C6
N4–C7
N4–C17
C5–C17
C9–C14
C9–C17
C6–S1–C17
C14–S2–C18
N4–N3–C6
N3–N4–C7
N3–N4–C17
C6–N4–C7
C6–N4–C17
C7–N4–C17
C17–C5–C18
S1–C6–N3
S1–C6–C26
N3–C6–C26
N4–C7–C20
N4–C7–C27
1.748 (3)
1.867 (3)
1.741 (3)
1.757 (4)
1.369 (3)
1.293 (4)
2.215 (4)
1.417 (3)
1.477 (3)
1.510 (4)
1.387 (4)
1.523 (4)
90.35 (13)
103.0 (2)
112.6 (2)
118.5 (2)
118.1 (2)
150.8 (2)
85.6 (2)
S2–C14–C9
S2–C14–C21
S1–C17–N4
S1–C17–C5
S1–C17–C9
N4–C17–C5
N4–C17–C9
C5–C17–C9
123.3 (3)
117.3 (2)
102.3 (2)
107.4 (2)
107.2 (2)
111.3 (2)
111.8 (2)
115.8 (2)
122.5 (3)
117.3 (3)
121.5 (3)
120.5 (3)
ꢀ2.1 (2)
2.2 (2)
ꢀ115.1 (2)
119.9 (2)
ꢀ179.0 (2)
ꢀ20.2 (3)
23.0 (3)
ꢀ161.0 (3)
162.4 (4)
1.1 (2)
S2–C18–C5
S2–C18–C29
C6–C26–C10
C6–C26–C15
C17–S1–C6–N3
C6–S1–C17–N4
C6–S1–C17–C5
C6–S1–C17–C9
C17–S1–C6–C26
C14–S2–C18–C5
C18–S2–C14–C9
C18–S2–C14–C21
C14–S2–C18–C29
N4–N3–C6–S1
C6–N3–N4–C7
C6–N3–N4–C17
N4–N3–C6–C26
C7–N4–N3–C6
123.2 (2)
120.9 (3)
116.5 (2)
121.3 (2)
122.1 (3)
121.2 (3)
119.7 (3)
ꢀ174.6 (4)
0.9 (2)
178.0 (4)
ꢀ174.6 (4)
CH3 at d 1.25 as triplet, J = 7.0 Hz, CH2 at d 4.25 as quartet,
J = 7.0 Hz, in addition to the aromatic protons (13H) at d 6.89–7.63.
The scope of the reaction was extended further by replacing the
sulfur atom at position 10 in thioxanthene-9-thione 4a with oxy-
gen and the study of the reactivity of the xanthene-9-thione 4b to-
wards the same nitrile imines generated from hydrazonoyl
chlorides 5a–g under the same reaction conditions. The latter
derivative 4b gave the corresponding cycloaddition products
7a–g. In the case of C-phenyl-N-phenyl hydrazonoyl chloride 5a
was reacted with 4b under the same reaction condition to afford
3,5-diphenyl-spiro-xanthene-90,2-[1,3,4]thiadiazole 7a as only
one product.
Also, the cycloaddition of initrile imine generated in situ from
C-acetyl-N-aryl 5b–e and triethylamine to 4b afforded 3-aryl-5-
acetyl-spiro-xanthene-90,2-[1,3,4]thiadia-zole (7d–e) in high yields
(Scheme 2). The structures of the products of this cycloaddition are
in accordance with their NMR spectroscopic data and elemental
analyses. The 1H NMR of compound 7e as an example, showed
COCH3 at d 2.63, two doublet for 4-nitrophenyl at 7.15 and 8.07
with coupling constant J = 8.40 Hz in addition to the remaining
aromatic protons (8H) around d 7.33–7.66 as multiplet band, also
the mass spectrum of 7e showed the prominent ion peak at m/z
417 (M+, 36), m/z 316 (M+–C3H3NOS, 42), m/z 269 (M+–C6H2N3O2,
20) and m/z 211 (M+–C9H8N3O3, 100).
On the other hand, the thiooxo derivative 4b reacted with ni-
trile imine generated in situ from C-carboethoxy-N-aryl (phenyl
and 4-tolyl) 5f,g as described above to afford the only one product
7f,g, respectively (Scheme 2). The structure of the products 6f,g
were established by elemental analysis and spectral data (IR,
NMR and MS). The 1H NMR spectrum of 7g as an example, showed
CH3 at d 1.25 as triplet, J = 7.0 Hz, CH3 as singlet at d 2.23, CH2 at d
4.26 as quartet, J = 7.0 Hz, and the aromatic protons (12H) at d
6.95–7.85. Finally, the spiro structure of 6 and 7 is clearly evident
from the lack of a 13C signal for the thiooxo group and the presence
of a signal at 81.86 ppm due to a quaternary carbon of both com-
pounds as expected for the spiro-thiadiazolo derivatives. Its 13C
NMR spectrum of 7g showed the spiro-carbon at 81.86, C@N at
148.03 and C@O at 159.78 ppm.
Spiro-thioxanthene- or spiro-xanthene-90,2-[1,3,4]thiadiazole deriva-
tives (6a–g, 7a–g): general procedure. A mixture of compound 4a,b
(0.01 mol) and the appropriate hydrazonoyl chlorides 5a–g
(0.01 mol) in dry benzene (30 mL) and 4 drops of triethylamine,
was stirred under reflux for 3–5 h (TLC control). The solvent was
evaporated under reduced pressure. The solid produced was washed
three times with 30 mL methanol and crystallized from an
appropriate solvent to produce 6a–g and 7a–g, respectively, in high
yields.
3,5-Diphenyl-spiro-thioxanthene-90,2-[1,3,4]thiadiazole (6a). The
compound was obtained from 4b and N-phenylbenzenecarbohyd-
razonoyl chloride 5a, as yellow needles (from dioxane), mp 215–
217 °C; IR: 3038 (CH aryl), 1594 (C@N); 1H NMR (d, ppm): 6.79
ꢀ7.63 (m, 18H, Ar–H); MS (m/z), 422 (M+, 100); Analysis:
C26H18N2S2 (422.56); Requires: C, 73.90; H, 4.30; N, 6.63; S,
15.17. Found: C, 73.87; H, 4.27; N, 6.59; S, 15.14.
5-Acetyl-3-phenyl-spiro-thioxanthene-90 ,2-[1,3,4]thiadiazole (6b).
The compound was obtained from 4b and 2-oxo-N-phenylpropane
hydrazonoyl chloride 5b, as yellow needles (from ethanol/dioxane)
(1:1), mp 186–188 °C; IR: 1668 (CO), 1592 (C@N). 1H NMR (d,
ppm); 2.60 (s, 3H, CH3), 6.91–7.61 (m, 13H, Ar–H); Analysis:
C22H16N2OS2 (388.50); Requires: C, 68.01; H, 4.15; N, 7.21; S,
16.50. Found: C, 67.97; H, 4.12; N, 7.19; S, 16.48.
5-Acetyl-3- (4-bromophenyl)-spiro-thioxanthene-90,2-[1,3,4]thia-
diazole (6c). The compound was obtained from 4b and 2-oxo-N-
(4-bromophenyl)propane hydrazonoyl chloride 5c, as yellow crys-
tals (from dioxane), mp 211–213 °C; IR: 1668 (CO), 1594 (C@N). 1H
NMR (d, ppm); 2.57 (s, 3H, CH3), 6.86–7.57 (m, 12H, Ar–H); MS (m/
z), 469 (M++2, 36), 467 (M+, 75); Analysis: C22H15BrN2OS2 (467.39);
Requires: C, 56.53; H, 3.23; N, 5.99; S, 13.72. Found: C, 56.50; H,
3.19; N, 5.95; S, 13.70.
The anti-inflammatory activity of the synthesized compounds
was evaluated by the carrageenan induced paw edema method.

H. N. Hafez et al. / Bioorg. Med. Chem. Lett. 18 (2008) 4538–4543
4541
Table 3
C–S, C–N bond formation at the tertiary carbon of 9H-xanthen-9-thione with nitrile imines
Substrate
Hydrazonoyl chloride 5a–g
Producta (6, 7a–g)
No: Timeb (h)
Yieldc (%)
Cl
N
H
N
N
3a; 3
4a; 3
88
77
S
N
C6H5 C6H5
(5a)
(6a)d,7a
X
H3COC
N
H
Cl
N
S
N
N
3b; 3
4b; 4
86
75
H3COC
C6H5
(5b)
X
6b,7b
H3COC
N
H
N
Br
Cl
N
S
N
3c; 4
4c; 3
79
80
H3COC
C6H4-Br
(5c)
X
6c,7c
H3COC
S
N
Cl
H
N
Cl
N
S
N
3d; 4
4d; 4
76
81
H3COC
C6H4-Cl
X
(5d)
4a,b
X
6d.7d
H3COC
N
H
N
NO2
Cl
N
S
N
3e; 5
4e; 3
78
72
H3COC
C6H4-NO2
(5e)
X
6e,7e
C2H5OOC
N
Cl
N
H
N
N
S
3f; 3
4f; 2
83
75
C2H5OOC
C6H5
(5f)
X
6f,7f
C2H5OOC
N
CH3
Cl
N
H
N
S
N
3g; 3
4g; 2
89
80
C2H5OOC
C6H4-CH3
(5g)
S
6g,7g
a
b
c
Products were characterized by IR, 1H, 13C NMR, MS.
Reactions were monitored by TLC.
Yields of the isolated products.
d
The structure was confirmed by X-ray.
5-Carboxyethyl-3-phenyl-spiro-thioxanthene-90,2-[1,3,4]thiadia-
1.25 (t, 3H, J = 7.0 Hz, CH3CH2), 4.25 (q, 2H, J = 7.0 Hz, CH3CH2),
6.89–7.63 (m, 13H, Ar–H); Analysis: C23H18N2O2 S2 (418.52); Re-
quires: C, 66.00; H, 4.33; N, 6.69: S, 15.32. Found: C, 66.01; H,
4.29; N, 6.65; S, 15.29.
zole (6f). The compound was obtained from 4b and chloro(phen-
ylhydrazono)ethylacetate 5f, as yellow crystals (from ethanol),
mp 190–193 °C; IR: 1698 (CO), 1592 (C@N). 1H NMR (d, ppm);

4542
H. N. Hafez et al. / Bioorg. Med. Chem. Lett. 18 (2008) 4538–4543
Table 4
pended in 1.0% CMC given orally 1 h before the carrageenin treat-
ment. The volume was measured before and after 4 h of
carrageenin treatment using a pleythysmometer.
Pharmacological activities anti-inflammatory and analgesic activities (Writhing test)
Compound Dose
(mg/kg,
Anti-inflammatory
activity (mean
Dose (mg/kg, Analgesic
1% CMC)
activity (mean
Analgesic assay (Writhing test). Mice were kept individually in
the test cage before acetic acid injection and habituated for
30 min. Screening of analgesic activity was performed after po
administration of test compounds at a dose of 70 mg/kg body
mass. The compounds, which exhibited good anti-inflammatory
activity comparable to that of ibuprofen, were screened for analge-
sic activity. All compounds were dissolved in 1.0% CMC solution.
One group was kept as control and received po 1% CMC. After 1 h
of drug administration, 0.10 mL of 1% acetic acid solution was gi-
ven to mice intraperitoneally. The acetic acid induced writhing
test29 showed stretching movements involving arching of the back,
elongation of the body, and extension of hind limbs which were
counted for 5–15 min of acetic acid injection.
Acute toxicity determination (LD50). Male Sprague–Dawley rats
(200–250 g) were housed individually in stainless steel cages. Rats
were divided into four groups under 12 h light–dark periods. Dif-
ferent doses were used for each group separately (25, 50, 75,
100 mg/kg BW) as oral gavages. The rats were observed for possi-
ble incidence of death or other behavioral changes.
1% CMC) inhibition SEM %)
inhibition SEM, %)
Control
6a
6b
6d
6e
6g
7a
7b
—
—
70
70
70
70
70
70
70
70
70
70
70
85 1.9b
75 1.7a
82 1.7b
86 1.7b
71 2.6a
82 0.9a
79 0.8a
76 2.1a
82 2.0c
84 2.0c
92 1.0
70
—
70
70
—
70
—
—
59 0.5a
—
57 0.9a
73 0.9a
—
71 1.2a
—
7c
7d
7e
—
70
70
70
72 1.1a
56.6 1.1a
83.5 0.7a
Ibuprofen
Anti-inflammatory and analgesic activities of the test compounds were measured
with respect to the control and compared with respect to the standard drug.
a
p < 0.0001.
b
p < 0.001.
p < 0.05.
c
5-Carboxyethyl-3-(4-tollyl)-spiro-thioxanthene-90,2-[1,3,4]thiadi-
azole (6g). The compound was obtained from 4b and chloro(4-toll-
ylhydrazono)ethylacetate 5g, as yellow crystals (from dioxane), mp
255–267 °C; IR: 1696 (CO), 1590 (C@N). 1H NMR (d, ppm); 1.27 (t,
3H, J = 7.0 Hz, CH3CH2), 2.20 (s, 3H, CH3), 4.25 (q, 2H, J = 7.0 Hz,
CH3CH2), 6.80–7.59 (m, 12H, Ar–H); MS (m/z), 432 (M+, 100); Anal-
ysis: C24H20N2O2 S2 (432.55); Requires: C, 66.63; H, 4.66; N, 6.47: S,
14.82. Found: C, 66.59; H, 4.63; N, 6.45; S, 14.79.
Statistical analysis. All statistical analyses were done by spss ver-
sion 10 by one-way ANOVA using Dunnett’s test.
CCDC-685500 (6a) contains the supplementary crystallographic
data for this paper. These data can be obtained free of charge from
the Cambridge Crystallographic Data Centre via www.ccdc.cam.a-
c.uk/data_request/cif.
Acknowledgments
3,5-Diphenyl-spiro-xanthene-90,2-[1,3,4]thiadiazole (7a). The
compound was obtained from 4a and N-phenylbenzene-carbo-
hydrazonoyl chloride 5a, as yellow needles (from ethanol), mp
195–197 °C; IR: 3031 (CH aryl), 1590 (C@N). 1H NMR (d, ppm);
6.72–7.68 (m, 18H, Ar–H); MS: m/z (%), 406 (M+, 85), 297 (12),
211 (27), 193 (84), 90 (100); Analysis: C26H18N2OS (406.50); Re-
quires: C, 76.82; H, 4.46; N, 6.89; S, 7.88. Found: C, 76.79; H,
4.39; N, 6.86; S, 7.85.
Authors thank Prof. Dr. F.A. Badria Professor of Pharmacology
and Head of Pharmacological Department, Head of Drug Discovery
Unit, Head of Liver Research Lab. Consultant in herbal and Alterna-
tive Medicine, Faculty of Pharmacy Mansoura University for per-
forming pharmacological activities evalution.
References and notes
5-Acetyl3-phenyl-spiro-xanthene-90,2-[1,3,4]thiadiazole (7b). The
compound was obtained from 4a and 2-oxo-N-phenylpropane
hydrazonoyl chloride 5b, as yellow needles (from ethanol), mp
190–192 °C; IR: 1663 (CO), 1595 (C@N). 1H NMR (d, ppm); 2.61
(s, 3H, CH3), 6.92–7.65 (m, 13H, Ar–H); MS: m/z (%), 372 (M+,
84), 271 (84), 270 (72), 269 (11), 212 (100); Analysis: C22H16N2O2S
(372.44); Requires: C, 70.94; H, 4.33; N, 7.52; S, 8.61. Found: C,
70.91; H, 4.29; N, 7.40; S, 8.57.
1. Hegab, M. I.; El-Gazzar, A. B. A.; Gad, F. A.; Ellithey, M. J. Sulfur Chem. 2007, 28,
101.
2. El-Gazzar, A. B. A.; Scholten, K.; Guo, Y.; Weibenbach, K.; Hitzler, M. G.; Roth,
G.; Fischer, H.; Jochims, J. C. J. Chem. Soc., Perkin Trans. 1 1999, 1999.
3. El-Gazzar, A. B. A.; Hegab, M. I.; Hassan, N. A. Sulfur Lett. 2002, 25, 45.
4. El-Gazzar, A. B. A.; Hegab, M. I.; Hassan, N. A. Sulfur Lett. 2002, 25, 161.
5. El-Gazzar, A. B. A.; Gaafar, A. M.; Aly, A. S. J. Sulfur Chem., 2008, (in press).
6. Jiang, H.; Zhao, J.; Han, X.; Zhu, S. Tetrahedron 2006, 62, 11008.
7. Padwa, A.. In Comprehensive Organic Chemistry; Trost, B. M., Flemin, I., Eds.;
Pergmon: Oxford, 1991; Vol. 4, p 1069.
Pharmacology Animals both sex of Swiss mice weighing 25–30 g
were used in analgesic activity and adult male of Sprague–Dawley
rats weighing between 150 and 180 g were used in anti-inflamma-
tory activity, taking into account international principle and local
regulations concerning the care and use of laboratory animals.27
The animals were housed in groups of six and acclimatized to room
conditions for at least 2 days before the experiments. Food and
water were freely available up to the time of experiments. The food
was withdrawn on the day before the experiment, but free access
to water was allowed. All the compounds (70 mg/kg body mass)
and the reference NSAID ibuprofen (70 mg/kg body mass) were
suspended in 1% carboxymethyl cellulose (CMC) and administered
orally using an animal feeding needle. The control groups received
appropriate volumes of vehicle (1% CMC, oral) only.
Anti-inflammatory assay. This activity was performed by the fol-
lowing procedure of Winter et al.28 on groups of six animals each. A
freshly prepared suspension of carrageenin (1.0% m/V, 0.1 mL) was
injected in the plantar region of the right hind paw of each rat. One
group was kept as control and the animals of the other group were
pretreated with the test compounds (70 mg/kg body mass) sus-
8. Albert, A. C.; Joyce, F. G.; Arthur, D. S.; Donald, R. M.; William, F. S.; Joseph, B. S.;
Martin, J. G.; Robert, W. F.; Gerald, D. M. J. Med. Chem. 1976, 19, 1142.
9. Cederlund, H.; Mardh, P.-A. J. Antimicrob. Chemother. 1993, 32, 355.
10. Rios-Santamarina, R.; Garcia-Domenech, J. Eur. J. Pharm. Sci. 2004, 22, 271.
11. Vartanyan, R. S. J. Pharm. Chem. 1984, 18, 736.
12. Mehta, A.; Srivastava, S. K.; Gupta, J. B. Patent No. WO 2004056810, 2004.
13. Birnbrrg, N. C.; Weng, Q.; Liu, H.; Avruch, J.; Kyriakis, J. Patent No. WO
2004044219, 2004.
14. Chibale, K.; Visser, M.; von Schalkwyk, D.; Smith, P. J.; Saravanamuthu, A.;
Fairlamb, A. H. Tetrahedron 2003, 59, 2289.
15. Wu, C.-P.; Van Schalkwyk, D. A.; Taylor, D.; Smith, P. J.; Chibale, K. Int. J.
Antimicrob. Agent 2005, 26, 170.
16. Chatterjee, S.; Iqbal, M.; Kauer, J. C.; Mallamo, J. P.; Senadhi, S.; Mallya, S.;
Bozyczko-Coyne, D.; Siman, R. Bioorg. Med. Chem. Lett. 1996, 6, 1619.
17. Wichmann, J.; Bleicher, K.; Vieira, E.; Woltering, T.; Knoflach, F.; Mutel, V.
Farmaco 2002, 57, 989.
18. Vieira, E.; Huwyler, J.; Jolidon, S.; Knoflach, F.; Mutel, V.; Wichmann, J. Bioorg.
Med. Chem. 2005, 15, 4628.
19. Naya, A.; Sagara, Y.; Ohwaki, K.; Saeki, T.; Ichasawa, Y.; Naguchi, K.; Ohtake, N.
J. Med. Chem. 2001, 44, 1429.
20. Naya, A.; Ishikawa, M.; Matsuda, K.; Ohwaki, K.; Saeki, T.; Naguchi, K.; Ohtake,
N. Bioorg. Med. Chem. 2003, 11, 875.
21. Fuoromadi, A.; Pournounourmohammadi, S.; Soltani, F.; Asgharian-Rezaee,
M.; Dabiri, S.; Kharazmi, A.; Shafiee, A. Bioorg. Med. Chem. Lett. 2005, 15,
1983.

H. N. Hafez et al. / Bioorg. Med. Chem. Lett. 18 (2008) 4538–4543
4543
22. Dogan, N. H.; Duran, A.; Rollas, S.; Sener, G.; Gulen, D. Bioorg. Med. Chem. 2002,
26. Hegarty, A. F.; Cashoman, M.; Aylward, J. B.; Scott, F. L. J. Chem. Soc. B 1971, 57,
1879.
10, 2893.
23. Shufan, E. E.; Pedregosa, J. C.; Baldini, O. N.; Bruno-Blanch, L. Farmaco 1999, 54,
27. Olfert, E. D.; Cross, B. M.; McWilliam, A. A., Eds. Canadian Council of Animal
Care Guide to the Care and Use of Experimental Animals, 2nd ed.; 1993; Vol. 1.
28. Winter, C. A.; Risley, E. A.; Nuss, G. W. Proceedings of the Society for
Experimental Biology and Medicine, III, 1962; p 544.
29. Collier, H. D. J.; Dinnin, L. C.; Johnson, C. A.; Schneider, C. Br. J. Pharmacol.
Chemother. 1968, 32, 295.
838.
24. Kostakis, I. K.; Magiatis, P.; Pouli, N.; Marakos, P.; Skaltsounis, A. –L.; Pratsinis,
H.; Leonce, S.; Pierre, A. J. Med. Chem. 2002, 45, 2599.
25. Wolkoff, P.; Steven Nemeth, T.; Gibson, S. M. Can. J. Chem. 1975, 53,
3211.