organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
ISSN 0108-2701
2,4-Bis(o-tolyl)-3-azabicyclo[3.3.1]-
nonan-9-one
L. Vijayalakshmi,a V. Parthasarathi,a* M. Venkatrajb and
R. Jeyaramanb
aDepartment of Physics, Bharathidasan University, Tiruchirappalli 620 024, India,
and bDepartment of Chemistry, Bharathidasan University, Tiruchirappalli 620 024,
India
Correspondence e-mail: sarati@bdu.ernet.in
Figure 1
The molecular structure of (I) showing 50% probability displacement
ellipsoids. H atoms have been omitted for clarity.
Received 13 March 2000
Accepted 27 June 2000
The crystal structure of the title compound, C22H25NO,
con®rms that the bicyclic ring system adopts the chair±chair
conformation. The phenyl rings are equatorially disposed with
respect to the bicyclic ring. There is a slight deviation from the
chair conformation in the case of the cyclohexane ring.
Experimental
A mixture of cyclohexanone (0.1 mol), o-tolualdehyde (0.2 mol) and
absolute ethanol (75±100 ml) was added to a warm solution of
ammonium acetate (0.15±0.20 mol) in absolute ethanol (200±250 ml).
The mixture was gently warmed on a hot plate until the yellow colour
changed to orange. Dry ether (100 ml) was added to the reaction
mixture after cooling and the solution was kept for 5 d. Pale-yellow
crystals of the ketone separated out and were washed with ethanol±
ether and then recrystallized from benzene±petroleum ether (b.p.
333±353 K) [yield 35±40%, m.p. 490±491 K].
Comment
The bicyclic [3.3.1]nonane ring can exist in chair±chair,
chair±boat and boat±boat conformations. Among these, the
chair±chair conformation is the most favourable. In the
present study of the title compound, (I), the bicyclic ring
system also adopts the chair±chair conformation.
Crystal data
3
C22H25NO
Mr = 319.43
Dx = 1.211 Mg m
Cu Kꢁ radiation
Cell parameters from 25
re¯ections
Monoclinic, P21=a
Ê
a = 7.692 (3) A
ꢂ = 2±25ꢁ
ꢃ = 0.564 mm
T = 293 (2) K
Ê
b = 16.825 (3) A
1
Ê
c = 13.7247 (18) A
ꢀ = 99.428 (18)ꢁ
3
Ê
V = 1752.1 (8) A
Z = 4
Rectangular block, pale yellow
0.15 Â 0.12 Â 0.10 mm
Data collection
Rigaku AFC-7S diffractometer
!/2ꢂ scans
Rint = 0.030
ꢂmax = 70.08ꢁ
Absorption correction: scan
(North et al., 1968)
Tmin = 0.928, Tmax = 0.942
3578 measured re¯ections
3312 independent re¯ections
2380 re¯ections with I > 2ꢄ(I)
h = 0 ! 9
k = 0 ! 20
l = 16 ! 16
In the cyclohexane ring of (I), atoms C7 and C9 deviate
from the C8/C1/C5/C6 plane by
3 standard re¯ections
every 100 re¯ections
intensity decay: negligible
0.537 (4) and
Ê
0.720 (3) A, respectively, indicating a departure from the
ideal chair conformation (Brown et al., 1965; Webb &
Becker, 1967). The piperidine ring has near ideal chair
conformation. The phenyl rings are equatorially disposed with
respect to the piperidine ring, with the torsion angles
Re®nement
Re®nement on F2
R[F2 > 2ꢄ(F2)] = 0.064
wR(F2) = 0.206
S = 1.101
3312 re¯ections
222 parameters
H atoms treated by a mixture of
independent and constrained
re®nement
w = 1/[ꢄ2(Fo2) + (0.1042P)2
+ 0.6146P]
where P = (Fo2 + 2Fc2)/3
(Á/ꢄ)max < 0.001
C9ÐC5ÐC4ÐC16
177.9 (2) and C10ÐC2ÐC1ÐC9
179.2 (2)ꢁ. They are oriented at an angle of 29.4 (1)ꢁ to each
other. The orientations of the two o-tolyl groups are such that
their methyl groups point towards the carbonyl group in the
fused-ring system.
Áꢅmax = 0.34 e A
3
Ê
3
Ê
0.43 e A
Áꢅmin
=
Extinction correction: SHELXL97
(Sheldrick, 1997)
Extinction coef®cient: 0.0067 (10)
ꢀ
1240 # 2000 International Union of Crystallography Printed in Great Britain ± all rights reserved
Acta Cryst. (2000). C56, 1240±1241
Vijayalakshmi
