organic compounds
Acta Crystallographica Section C
Crystal Structure
triazole-3-thiols have been condensed with aromatic
carboxylic acids to yield a series of 3,6-(4-aryl/4-heteroaryl)-
Communications
1
,2,4-triazolo[3,4-b][1,3,4]thiadiazoles. Phosphorous oxychlor-
ide is used as a cyclizing agent ( CË etin, 2004; Holla, Gonsalves
Shenoy, 1998). In view of these important properties, the
ISSN 0108-2701
&
present single-crystal X-ray diffraction study of the title
compound, (II), was carried out in order to investigate this
bicyclic system and to con®rm the assigned structure.
6
-Phenyl-3-(4-pyridyl)-1,2,4-triazolo-
[
3,4-b][1,3,4]thiadiazole
a
a
b
È
Muharrem Din cË er, Namõk Ozdemir, * Ahmet CË etin,
b
a
Ahmet Cansõz and Orhan B uÈ y uÈ kg uÈ ng oÈ r
a
Department of Physics, Faculty of Arts and Sciences, Ondokuz Mayõs University,
b
5
5139 Samsun, Turkey, and Department of Chemistry, Faculty of Arts and Sciences,
Fõrat University, 23119 Elazõ gÆ , Turkey
In the present study, the new compound 6-phenyl-
-(4-pyridyl)-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole, (II), was
3
synthesized in 70% yield by the reaction of 4-amino-5-(4-
pyridyl)-4H-1,2,4-triazole-3-thiol, (I), benzoic acid and phos-
phorous oxychloride. The reaction sequences depicted in the
scheme were followed to obtain the new compound. The
Received 15 August 2005
Accepted 10 October 2005
Online 27 October 2005
1
The title compound, C H N S, has been synthesized and
5
structure of this compound has been con®rmed by IR, H
1
4
9
1
NMR and C NMR spectroscopies.
3
characterized both spectroscopically and structurally. The
triazolo±thiadiazole system, the pyridine ring and the phenyl
ring are all planar. The plane of the triazolo±thiadiazole
Compound (II) (Fig. 1) consists of a fused triazolo±thia-
diazole system, one pyridine ring and one phenyl ring. The
four rings are almost coplanar. As expected, the 1,2,4-triazole
and pyridine rings are planar, which can be attributed to a
wide range of electron delocalization. The plane of the tria-
zolo±thiadiazole system forms dihedral angles of 1.53 (13) and
ꢀ
system forms dihedral angles of 1.53 (13) and 7.55 (12) with
the planes of the pyridine and phenyl rings, respectively. In the
molecule, there are two intramolecular interactions of types
CÐHÁ Á ÁN and CÐHÁ Á ÁS. Intermolecular CÐHÁ Á ÁN inter-
actions involving a phenyl CH group and a triazole N atom
lead to the formation of a one-dimensional chain. In the
crystal structure, two types of ꢀ±ꢀ interactions affect the
packing of the molecules. In addition, there are intermolecular
ꢀ
7.55 (12) with the planes of the pyridine and phenyl rings,
respectively.
The N1 C1 and N2 C2 bond distances [average =
Ê
1.315 (2) A] are in good agreement with those found for
È
structures containing the 1,2,4-triazole ring (Ozbey et al., 2000;
Bruno et al., 2003). In (II), the presence of the pyridine ring in
the 3-position of the triazole ring leads to an elongation of the
Ê
non-bonded SÁ Á ÁN contacts of 2.870 (2) A, which may cause
steric hindrance.
Ê
Ê
N1ÐN2 bond length to 1.395 (2) A. This bond is 1.371 (2) A
in 5-amino-3-tri¯uoromethyl-1H-1,2,4-triazole (Borbulevych
et al., 1998), in which an electron-withdrawing group is bound
to the 3-position of the triazole ring. The thiadiazole moiety
Comment
The prevalence of resistant infections has decreased the
applicability of existing chemotherapeutic and chemo-
preventive antimicrobial agents and stimulated the search for
new compounds. The 1,2,4-triazole nucleus and the nitrogen-
bridged heterocycles derived from it have recently been
incorporated into a variety of compounds with antibacterial
(
Holla & Kalluraya, 1988), antifungal (Prasad et al., 1989) and
antiparasitic (El-Dawy et al., 1983) properties. In addition, it is
well known that derivatives of 1,2,4-triazole exhibit anti-
in¯ammatory (Unangst et al., 1992; Mullican et al., 1993),
antiviral (Jones et al., 1965), antimicrobial (Shams El-Dine &
Hazzaa, 1974; Misato et al., 1977; Koparõr et al., 2004) and
antidepressant activities (Kane et al., 1988), the last being
usually explored by the forced-swim test (Porsolt et al., 1977;
Vamvakides, 1990). Among the pharmacological pro®les of
1
,2,4-triazoles, their antimicrobial, anticonvulsant and anti-
Figure 1
depressant properties seem to be the best documented.
Several thiadiazoles ®nd important applications in the ®elds
of medicine, agriculture and industry (Holla, Sarojini &
Gonsalves, 1998). 4-Amino-5-(4-aryl/4-heteroaryl)-4H-1,2,4-
A view of the molecule of compound (II), showing the atomic numbering
scheme. Displacement ellipsoids are drawn at the 50% probability level.
Intramolecular non-bonded CÐHÁ Á ÁS and CÐHÁ Á ÁN contacts are
represented by dashed lines.
Acta Cryst. (2005). C61, o665±o667
DOI: 10.1107/S0108270105032403
# 2005 International Union of Crystallography o665
Dincer, Muharrem
