Asian Journal of Chemistry; Vol. 27, No. 3 (2015), 969-973
A
SIAN
J
OURNAL OF HEMISTRY
C
Synthesis and Crystal Structures of 2-Amino-4-methyl-5,6,7,8-tetrahydroquinoline-3-carbonitrile
and 2-Amino-4-phenyl-4a,5,6,7-tetrahydro-4H-naphthalene-1,3,3-tricarbonitrile
1
1,*
2
AISHA SADDIQA , IFTIKHAR HUSSAIN BUKHARI , MUHAMMAD NAWAZ TAHIR ,
1,*
1
3,4
MATLOOB AHMAD , MUHAMMAD SHAFIQ and MUHAMMAD NADEEM ARSHAD
1
2
3
4
Department of Chemistry, Government College University, Faisalabad-38000, Pakistan
Department of Physics, University of Sargodha, Sargodha, Pakistan
Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, Jeddah 21589 Saudi Arabia
Corresponding authors: E-mail: pdiftikhar@yahoo.com; matloob_123@yahoo.com
Received: 9 April 2014; Accepted: 19 June 2014; Published online: 19 January 2015;
*
AJC-16706
2
-Amino-4-methyl-5,6,7,8-tetrahydroquinoline-3-carbonitrile with m.f. C11
of cyclohexanone, malononitrile and acetaldehyde. However, in an effort to synthesize another analogue of I using benzaldehyde in
placement of acetaldehyde, 2-amino-4-phenyl-4a,5,6,7-tetrahydro-4H-naphthalene-1,3,3-tricarbonitrile (II) [C19 ] was formed. The
H
13
N
3
was synthesized using simple multicomponent reaction
H
16
N
4
compounds I and II were crystallized in triclinic and orthorhombic crystal system with space group P-1 and Pbca. The two carbon atoms
in tetrahydroquinoline-3-carbonitrile were disordered over two positions which were refined using EADP constraint. The dihedral angle
puckering parameters of different planes were measured. It is found that both of these molecules are involved in classical N-H…N type
2
2
2
hydrogen bonding interaction which forms dimers through the formation of different ring motifs i.e. R
2
(8) and R (12). In quinoline-3-
carbonitrile N-H…N interactions forms sheets along ab plane while in naphthalene-1,3,3-tricarbonitrile infinite two dimensional network
stabilize the crystal structure along (0 0 1) plane.
Keywords: Carbonitrile, Synthesis, Crystal structures, C–N···H Hydrogen bonding.
INTRODUCTION
EXPERIMENTAL
Quinoline and hydroquinoline ring systems occupy a
The title compounds were synthesized by using reported
14
significant position in the research ongoing in medicinal
chemistry. A long range of quinoline compounds, natural and
synthetic are in clinical use for the treatment of malaria. Recent
literature contains several research articles dealing with the new
synthetic routes and biological profiles of such compounds,
for example, 4H-pyrano[3,2-h]quinoline and 7H-pyrimido-
methodology for the tetrahydroquinoline precursor compound
I. However, in an attempt to synthesize analogue of Iby replacing
benzaldehyde for acetaldehyde in the same method, the unex-
pected formation of 2-amino-4-phenyl-4a,5,6,7-tetrahydro-4H-
naphthalene-1,3,3-tricarbonitrile (II) was resulted.
Compound I: A mixture of cyclohexanone (0.98 g, 0.01
mol) with acetaldehyde (0.44 g, 0.01 mol), malononitrile
(0.66 g, 0.01 mol) and ammonium acetate (1.15 g, 0.015 mol)
in ethanol (20 mL) was refluxed for 1 h. The reaction mixture
was then stirred overnight at room temperature and the
obtained solid was recrystallized from ethanol to obtain pure
product. Yield, 40 %, m.p. 279 °C (Scheme-I).
[
4',5':6,5]pyrano[3,2-h]quinoline derivatives are recently
1
discovered as potent antitumor agents . Some new tetrahydro-
quinoline derivatives are found as plasma cholesteryl ester
transfer protein (CETP) inhibitors , while 2-oxo-1,4-disubsti-
2
tuted-1,2,5,6-tetrahydro-benzo[h]quinoline-3-carbonitriles are
3
reported as cytotoxic and antiviral agents . They have been
observed to bind efficiently with DNA and exhibit antitumour
Compound II: A mixture of cyclohexanone (0.98 g, 0.01
mol) with benzaldehyde (1.08 mL, 0.01 mol), malononitrile
(0.66 g, 0.01 mol) and ammonium acetate (1.15 g, 0.015 mol)
in ethanol (20 mL) was refluxed for 1 h. The reaction mixture
was then stirred overnight at room temperature and the
obtained solid was recrystallized from ethanol to obtain pure
product. Yield, 62 %, m.p. 253 °C (Scheme-I).
4
5
6
activity , antifungal , HIV entry inhibitors and nonsteroidal
7
selective androgen receptor modulators . During our search
for new biologically active heterocyclic compounds, we have
8
reported quinoline compounds as potent HIV inhibitors ,
9
antileishmanial agents and benzothiazine compounds as anti-
1
0-12
13
HIV agents , antioxidants and antibacterial agents .
Saddiqa, Aisha
