Synthesis, spectral characterization, single crystal and conformational study of 1,5-dimethyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-one derivatives

Article abstract of DOI:10.1016/j.molstruc.2011.12.045

1,5-Dimethyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-one 1 and their derivatives 2-8 were obtained by condensation of 2,6-dimethyl cyclohexanone, Ammonium acetate and substituted aromatic aldehydes and characterized by FT-IR, FT-Raman, ¹H NMR,

Full text of DOI:10.1016/j.molstruc.2011.12.045

Journal of Molecular Structure 1012 (2012) 119–125
Contents lists available at SciVerse ScienceDirect
Journal of Molecular Structure
journal homepage: www.elsevier.com/locate/molstruc
Synthesis, spectral characterization, single crystal and conformational study
of 1,5-dimethyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-one derivatives
b
R. Venkateswaramoorthi a, J. John Francis Xavier a, K. Krishnasamy a, , H. Saleem
⇑
a Department of Chemistry, Annamalai University, Annamalai Nagar 608 002, India
b Department of Physics, Annamalai University, Annamalai Nagar 608 002, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 7 July 2011
Received in revised form 6 December 2011
Accepted 27 December 2011
Available online 4 January 2012
1,5-Dimethyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-one 1 and their derivatives 2–8 were obtained
by condensation of 2,6-dimethyl cyclohexanone, Ammonium acetate and substituted aromatic aldehydes
and characterized by FT-IR, FT-Raman, 1H NMR, 13C NMR, GC–MS, HOMOCOSY, HSQC, NOESY, single crys-
tal X-ray diffraction analysis and theoretical DFT calculation. Compound 1 crystallized in the Triclinic sys-
0
0
0
tem, space group P-1 with a = 6.8950(5) ÅA, b = 11.5889(9) ÅA, c = 11.9172(9) ÅA,
a
= 76.277(4)°,
0
b = 78.000(3)°,
c
= 72.920(4)°, V = 874.41(12) ÅA3 and Z = 2. 1,5-Dimethyl-2,4-diphenyl-3-azabicy-
Keywords:
clo[3.3.1]nonan-9-one 1 and their derivatives 2–8 were exist in boat–chair conformation with equatorial
orientation of all the substituents at piperidine ring (two phenyl rings at C-2 and C-4 position, two methyl
substituents at C-1 and C-5 position) of compound 1. In the crystal structure of compound 1, the mole-
cules are connected by NAHꢀ ꢀ ꢀO@C intermolecular hydrogen bonds. The existence of boat–chair confor-
mation was confirmed by single crystal X-ray diffraction analysis and theoretical DFT calculation.
Ó 2012 Published by Elsevier B.V.
2,4-Diphenyl-3-azabicyclo[3.3.1]nonan-9-
one
1H–1H COSY
HSQC
NOESY
Conformational study
Crystal structure
1. Introduction
ary amine, cyclic carbonyl group site [17–21]. Molecules with the
3-azabicyclo[3.3.1]nonan-9-one nucleus are a great interest due
The correlation of reactivity and stability of heterocyclic com-
pounds with their predominant conformation has provided a valu-
able method of assigning the stereo chemical conformation of the
isomers [1–6]. Multicomponent reactions are nowadays of particu-
lar importance in synthetic organic chemistry since they offer one
spot combination of more than two components in one step allow-
ing direct access to target molecule [7–11]. The extensive use of
conformational analysis in the investigation of problems related
to the geometry of molecules dates back to the pioneering papers
by Irieppa [12–15] in which the dependence of the reactivity of
many cyclohexane derivatives on their conformations was dis-
tinctly brought out. All 1,5-dimethyl-2,4-diaryl-3-azabicyclo[3.3.1]
nonan-9-one 1–8 were synthesized with good yields by the litera-
ture procedure [16] of the one pot multicomponent condensation
of ammonium acetate, substituted benzaldehydes and substituted
cyclohexanone (1:2:1 ratio).
to their present in a wide variety of naturally occurring alkaloids
and biological activities [22–24]. 2,4-diaryl-3-azabicyclo[3.3.1]
nonan-9-one derivatives were showed very good antitumor [25]
and antimicrobial [26] activities. Stereo chemical assignments of
all the compounds were unambiguously achieved with the help
of FT-IR, FT-Raman, 1H NMR, 13C NMR, GC–Mass, HOMOCOSY,
HSQC and NOESY spectral techniques and single crystal X-ray dif-
fraction analysis.
2. Experimental
2.1. General
TLC was carried out to monitor the course of the reaction and pur-
ity of the product. The melting points were recorded in open capil-
laries and are uncorrected. The FT-IR spectra were recorded on a
AVATAR-330FT-IR spectrophotometer (thermo Nicolet), assisted
by a computer, in the solid state (KBr) and noteworthy absorption
levels (reciprocal centimeters) alone are listed. The FT-Raman spec-
trum of PDPO was recorded using the 1064 nm live of Nd YAG laser
as excitation wavelength in the region 10–3500 cmꢁ1 on a Bruker
model RFS100/s spectrophotometer equipped with FRA 106
FT-Raman module accessory. 1H NMR spectra were recorded at
400 MHz on BRUKER AV-III 400 MHz spectrometer using CDCl3 as
In the present paper, we report the synthesis, structural and the
conformational studies of a series of 1,5-dimethyl-2,4-diaryl-3-
azabicyclo[3.3.1]nonan-9-ones. 1,5-dimethyl-2,4-diaryl-3-azabi-
cyclo[3.3.1]nonan-9-ones as an important synthetic intermediate
for the preparation of various organic molecules through second-
⇑
Corresponding author.
E-mail address: krishbala56@yahoo.co.in (K. Krishnasamy).
0022-2860/$ - see front matter Ó 2012 Published by Elsevier B.V.
doi:10.1016/j.molstruc.2011.12.045

120
R. Venkateswaramoorthi et al. / Journal of Molecular Structure 1012 (2012) 119–125
7
R
R
O
9
8
6
R
R
O
R1
R1
CHO
1
2
5
4
CHO
R2
R3
R2
R3
R1
R2
3
N
H
Warm
EtOH
R1
R2
+
NH4OAc
R3
R3
R = CH3
Scheme 1. Schematic diagram of synthesis of 1,5-dimethyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-one (1).
solvent and TMS as internal standard. 13C NMR spectra were re-
corded 400 MHz on BRUKER AV-III 400 MHz spectrometer in CDCl3
and HOMOCOSY, HSQC and NOESY correlation spectra were re-
corded on BRUKER AV-III 400 MHz NMR spectrometer using stan-
dard parameters. For recording 1H NMR spectra, solution were
prepared by dissolving about 10 mg of the compound in 0.5 ml of
CDCl3. While for recording 13C NMR spectra, about 50 mg of the com-
pound was dissolved in the same volume of the solvent. 0.05 M solu-
tions of the sample prepared in CDCl3 were used for recording 2D
NMR spectra. Mass spectra were recorded on VARIAN CP-3800 Gas
Chromatograph (EI).
at 293 K. Bruker SMART APEXII area detector diffract meter was
used for the measurement of data. The collected data were reduced
using the SAINT program and structural refinement was carried out
by Full-matrix least-squares on F2 (SHELXL-97). Molecular graph-
ics employed include ORTEP and PLATON.
2.4. Theoretical methods
The theoretical calculations were performed at DFT level on a
Pentium IV/3.02 CH2 personal computer using curassian 0.3w
[27] program paueage, invoking gradient geometry optimization
[28]. The optimized structural parameters were used in the vibra-
tional frequency calculation at the DFT level to characterize all sta-
tionary points as minima. Then, vibrationally averaged nuclear
positions of compound were used for harmonic vibrational fre-
quency calculations resulting in FT-IR and FT-Raman frequencies
together with intensities and Raman depolarization ratios.
2.2. General procedure for preparing 1,5-dimethyl-2,4-diaryl-3-
azabicyclo[3.3.1]-nonan-9-ones (1–8)
The synthesis pathway leading to the title compound is given in
Scheme 1. Dry ammonium acetate (0.05 mol) was dissolved in
50 ml ethanol and the solution was mixed with substituted benz-
aldehyde (0.1 mol) and 2,6-dimethyl cyclohexanone (0.05 mol).
The mixture was heated to boil and allowed to stand at room tem-
perature overnight. 30 ml Conc. HCl was added and the hydrochlo-
ride salt was collected washed with mixture of ethanol and ether
(1:5 ratio). A suspension of the hydrochloride salt in acetone was
treated with strong liquid ammonia solution and the free base
was obtained by pouring water. The product was recrystallized
by ethanol. Analytical data of compound 1–8 shown in Table 1.
3. Result and discussion
3.1. IR spectral analysis of compounds
In IR spectra, the presence of carbonyl stretching frequency
around 1705–1695 cmꢁ1 confirm the bicyclic ketone formation. A
collection of bands observed in the region of 3315–3292 cmꢁ1
are due to NAH stretching frequency of piperidine ring. An absorp-
tion bands appeared in the region of 3084–2788 cmꢁ1 is ascribed
to aromatic and aliphatic CAH stretching frequencies. The FT-IR,
FT-Raman experimental and B3LYP/6-31 G (d,p) level basis set the-
oretical calculation spectra are given Fig. S1, Fig. S2, Fig. S3 and
Fig. S4, respectively. The FT-IR, FT-Raman experimental and
B3LYP/6-31 G (d,p) level basis set theoretical calculation vibra-
tional frequencies are given Table S1 (see Supplementary data).
2.3. X-ray data collection, structure solution and refinement
Single crystals suitable for diffraction were obtained by the slow
evaporation of a solution of the compound in ethanol. The colorless
crystal of the compound was mounted on a glass fiber with epoxy
cement for the X-ray crystallographic study. The selected crystal
data and data collections parameters of the compound collected
3.2. NMR spectral analysis of compound 1
In order to investigate the spectral assignments of reported
compounds 1–8, we have chosen compound 1 as the representa-
tive system. In 1H NMR spectra, methyl proton gives a singlet at
0.84 ppm with six proton integral value is assigned to CH3 protons
at C-1 and C-5. In the shielded region, there are two multiplets ob-
served at 1.49 and 2.11 ppm with two and three proton integral va-
lue. It is worthwhile to mention that the equatorial proton in the
methylene carbon of cyclohexane ring is highly deshieled than
the axial protons due to the anisotropy of CAC single bonds. Hence,
the deshielded multiplet at 2.11 ppm is assigned to equatorial pro-
tons at C-6 and C-8 carbons and the shielded multiplet at 1.49 ppm
Table 1
Analytical data for compounds 1–8.
Compounds
R
R1
R2
R3
Yield (%)
M.P. (°C)
M+ (m/z)
1
2
3
4
5
6
7
8
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
H
H
H
H
H
H
H
H
H
H
H
H
H
Br
F
H
Br
F
Cl
CH3
H
65
72
66
50
60
74
78
52
191–193
192–194
182–184
172–174
198–200
204–206
226–228
224–226
319
–
–
–
–
–
–
–
H
H
Cl

R. Venkateswaramoorthi et al. / Journal of Molecular Structure 1012 (2012) 119–125
121
Table 2
1H NMR chemical shifts of compounds 1–8 [d (ppm)].
CMD
H-6a, H-8a, H-7e, m, 3[H]
H-6e, H-8e, m, 2[H]
H-7a, m, 1[H]
CH3 s, 6[H]
H-2, H-4, s, 2[H]
NH s, 1[H]
CH3 s, 6[H]
Aromatic protons
1
2
3
4
5
6
7
8
1.49
1.51
1.51
1.51
1.47
1.52
1.52
1.53
2.11
2.04
2.07
2.04
2.11
2.10
2.11
2.11
3.48
3.35
3.38
3.35
3.46
3.32
3.37
3.37
0.84
0.82
0.82
0.83
0.82
0.84
0.86
0.85
3.48
3.90
3.92
3.91
3.88
3.88
3.93
3.90
1.88
1.80
1.85
1.81
1.80
1.87
1.89
1.78
7.30–7.53
7.19–7.76
7.04–7.52
7.26–7.47
7.15–7.42
7.23–7.67
6.99–7.27
7.26–7.53
2.35
Table 3
13C NMR Chemical shifts of compounds 1–8 [d (ppm)].
CMD C-1,
C-5
C-2,
C-4
C10,
C11
C-6,
C-8
C-7
C@O
Methyl Aromatic
and ipso
He
Ha
Ha
Ha
7
carbon
O
1
2
3
4
5
6
7
8
51.01 71.58 20.77 36.92 21.47
50.78 70.78 20.70 36.73 21.40
50.92 70.79 20.72 36.73 21.42
50.83 70.84 20.71 36.73 21.41
51.04 71.30 20.81 36.93 21.47
217.95
191.02
217.41
217.07
–
–
–
–
127.97–
139.81
121.85–
138.57
114.79–
163.64
128.26–
138.07
He
He
6
8
H3C
CH3
9
1
2
5
H
H
Ha
Ha
4
H
H
3
N
H
218.20 129.01 128.64–
137.38
50.81 70.98 20.71 36.78 21..40 216.76
–
–
–
122.29–
141.80
114.72–
163.91
127.28–
141.56
50.87 70.95 20.77 36.86 21.38
50.83 71.03 20.73 36.81 21.41
217.02
216.83
Fig. 1. Selected HSQC correlation of compound 1.
methyl group of the azabicyclic moiety. C-7 carbon gives correlation
with 1.49 ppm as a multiplet in the shielded region and 3.48 ppm as
a multiplet with one proton integral value in the deshielded region.
These correlations are obtained due to the C-7 axial and equatorial
protons. HSQC correlation of compound 1 shown in Fig. 1.
In the NOESY spectrum of compound 1, H-6a, H-8a and H-7e
protons gives NOE correlation with NH, H-6e, H-8e and H-7a pro-
tons. Likewise H-6e, H-8e protons gives NOE correlation with H-6a,
H-8a protons and phenyl protons. An H-7a proton gives NOE corre-
lation with H-7e, H-6e and H-8e protons. Methyl protons give NOE
correlation with H-6a, H-8a and benzylic protons. A benzylic pro-
ton gives NOE correlation with methyl, NH and aryl protons. NH
protons give NOE correlation with methyl, H-6e, H-8e, H-7a and
benzylic protons. These NOESY correlations are very much useful
to predict the adjacent proton present in the target molecule.
NOESY correlation of compound 1 shown in Fig. 2. HOMOCOSY
and NOESY correlation given Table S2 (see Supplementary data).
is assigned to axial protons at C-6 and C-8 carbons. Here, the
remaining one proton integration at 1.49 ppm is assigned to H-7e
proton. On comparing the H-7a and H-7e proton, the H-7a proton
resonated in the deshielded region at 3.48 ppm. This may be due to
the lone pair interaction between the H-7a proton and the NH pro-
ton. One singlet at 1.88 ppm is assigned to NH proton of piperidine
ring. Benzylic protons (H-2 and H-4) resonated at 3.48 ppm as a
singlet. In 1H NMR spectra, para proton of the phenyl ring gives
triplet at 7.30 ppm. Similarly meta protons of the phenyl ring res-
onated at 7.36 ppm as a triplet with two proton integral values
and ortho protons signal resonated at 7.53 ppm as a doublet with
two proton integral value. 1H NMR and 13C NMR chemical shift va-
lue of compounds 1–8 given in Table 2 and Table 3, respectively.
In the HOMOCOSY spectrum of compound 1, the multiplet ob-
served at 1.49 ppm exhibit strong cross peak with 2.11 ppm and
3.48 ppm. This suggest that two multiplet may be characteristics for
set of similar kinds of protons present due to axial or equatorial set
of protons present in C-6, C-8 and C-7 carbons. Likewise, C-6 and C-8
equatorial proton gives cross peak in HOMOCOSY spectrum, at
1.49 ppm in the shielded region and multiplet for one proton integral
value at 3.48 ppm in the deshielded region. This may be characteristics
for set of similar kinds of proton present in C-7 Carbon. Similarly C-7
equatorial proton gives cross peak in HOMOCOSY spectrum at
1.49 ppm as multiplet and 2.11 ppm multiplet for two proton integral
values and it’s resonated at shielded region and another one is
deshielded region. This may be characteristic with C-6 and C-8 axial
and equatorial protons in bridgehead cyclohexane ring moiety. Ben-
zylic protons give week cross peak with C-6, C-8 axial and C-7 equa-
torial position of the bridgehead protons of the cyclohexane ring
moiety.
3.3. NMR spectral data of compound 1–8
3.3.1. 2,4-Diphenyl-1,5-dimethylazabicyclo[3.3.1]nonan-9-one (1)
IR(KBr, cmꢁ1); 1698 (carbonyl); 3296 (NH); 1H NMR(CDCl3,
440 MHz, ppm); d 0.84 (s, 6H, CH3); 1.49 (m, 3H, 6a, 8a and 7e);
2.11 (m, 2H, 6e, 8e); 3.48 (m, 1H, 7a); 1.88 (s, 1H, NH); 3.93 (s,
2H, H-2, H-4); 7.30–7.53 (aromatic protons). 13C NMR (CDCl3,
400 MHz, ppm); d 20.79 (C-10, C-11); 36.92 (C-6, C-8); 21.47 (C-
7); 50.01 (C-1, C-5); 71.58 (C-2, C-4); 217.95 (carbonyl), 127.97–
139.81 (aromatic and ipso carbons).
3.3.2. Bis-(4-bromo)-2,4-diphenyl-1,5-
dimethylazabicyclo[3.3.1]nonan-9-one (2)
In the HSQC spectrum of compound 1, CH3 carbon cannot give
correlation with any other protons. This may characteristic bridged
IR(KBr, cmꢁ1); 1701 (carbonyl); 3314 (NH) ; 1H NMR(CDCl3,
440 MHz, ppm); d 0.82 (s, 6H, CH3); 1.51 (m, 3H, 6a, 8a and 7e);

122
R. Venkateswaramoorthi et al. / Journal of Molecular Structure 1012 (2012) 119–125
Table 4
O
Parameters for data collection and structure refinement of compound 1.
Crystal data
Compound 1
C22H25NO
Molecular formula
Molecular weight
CH3
319.43
9
Temperature
293 K
Crystal system, space group
Unit cell dimensions
Triclinic, P-1
H3C
0
a = 6.8950(4) ÅA
= 76.277(4)°
a
5
8
1
N
0
Ha
b = 11.5889(9) ÅA
b = 78.000(3)°
4
2
Ha
Ha
H
0
c = 11.9172(9) ÅA
Ha
c
= 72.920(4)°
6
Volume
874.41(12) A3
Z, calculated density
Absorption coefficient
F(000)
2
He
0.073 mmꢁ1
344
He
Theta range for data collection
Observed data [I > 2.0 sigma(I)]
Reflections collected/unique
R, WR2
1.8–28.4
3674
15767/4375[R(int) = 0.026]
0.0434, 0.1226
4375, 223
7
Ha
He
Nref, Npar
S
1.05
0
Min. and max resd. dens.
ꢁ0.25, 0.29 e ÅAꢁ3
Fig. 2. Selected NOESY correlation of compound 1.
2H, H-2, H-4); 7.23–7.67 (aromatic protons). 13C NMR (CDCl3,
400 MHz, ppm); d 20.71 (C-10, C-11); 36.78 (C-6, C-8); 21.40 (C-
7); 50.81 (C-1, C-5); 70.98 (C-2, C-4); 216.76 (carbonyl), 122.29–
141.80 (aromatic and ipso carbons).
2.05 (m, 2H, 6e, 8e); 3.35 (m, 1H, 7a); 1.80 (s, 1H, NH); 3.90 (s, 2H,
H-2, H-4); 7.19–7.76 (aromatic protons). 13C NMR (CDCl3,
400 MHz, ppm); d 20.70 (C-10, C-11); 36.73 (C-6, C-8); 21.40 (C-
7); 50.78 (C-1, C-5); 70.78 (C-2, C-4); 191.02 (carbonyl), 121.85–
138.57 (aromatic and ipso carbons).
3.3.7. Bis-(3-fluro)-2,4-diphenyl-1,5-dimethylazabicyclo[3.3.1]nonan-
9-one (7)
3.3.3. Bis-(4-fluro)-2,4-diphenyl-1,5-dimethylazabicyclo[3.3.1]nonan-
9-one (3)
IR(KBr, cmꢁ1); 1695 (carbonyl); 3298 (NH); 1H NMR(CDCl3,
440 MHz, ppm); d 0.86 (s, 6H, CH3); 1.52 (m, 3H, 6, 8a and 7e);
2.15 (m, 2H, 6e, 8e); 3.37 (m, 1H, 7a); 1.89 (s, 1H, NH); 3.93 (s,
2H, H-2, H-4); 6.99-7.27 (aromatic protons). 13C NMR (CDCl3,
400 MHz, ppm); d 20.77 (C-10, C-11); 36.86 (C-6, C-8); 21.38 (C-
7); 50.87 (C-1, C-5); 70.95 (C-2, C-4); 217.02 (carbonyl), 114.72–
163.91 (aromatic and ipso carbons).
IR(KBr, cmꢁ1); 1703 (carbonyl); 3326 (NH); 1H NMR(CDCl3,
440 MHz, ppm); d 0.82 (s, 6H, CH3); 1.51 (m, 3H, 6a, 8a and 7e);
2.07 (m, 2H, 6e, 8e); 3.38 (m, 1H, 7a); 1.85 (s, 1H, NH); 3.92 (s,
2H, H-2, H-4); 7.04–7.52 (aromatic protons). 13C NMR (CDCl3,
400 MHz, ppm); d 20.72 (C-10, C-11); 36.73 (C-6, C-8); 21.42 (C-
7); 50.92 (C-1, C-5); 70.78 (C-2, C-4); 217.41 (carbonyl), 114.79–
163.64 (aromatic and ipso carbons).
3.3.8. Bis-(3-chloro)-2,4-diphenyl-1,5-
dimethylazabicyclo[3.3.1]nonan-9-one (8)
3.3.4. Bis-(4-chloro)-2,4-diphenyl-1,5-
dimethylazabicyclo[3.3.1]nonan-9-one (4)
IR(KBr, cmꢁ1); 1695 (carbonyl); 3294 (NH); 1H NMR(CDCL3,
440 MHz, ppm); d 0.85 (s, 6H, CH3); 1.53 (m, 3H, 6a, 8a and 7e);
2.10 (m, 2H, 6e, 8e); 3.37 (m, 1H, 7a); 1.78 (s, 1H, NH); 3.90 (s,
2H, H-2, H-4); 7.26–7.53 (aromatic protons). 13C NMR (CDCl3,
400 MHz, ppm); d 20.73 (C-10, C-11); 36.81 (C-6, C-8); 21.41 (C-
7); 50.83 (C-1, C-5); 71.03 (C-2, C-4); 216.83 (carbonyl), 127.28–
141.56 (aromatic and ipso carbons).
R(KBr, cmꢁ1); 1705 (carbonyl); 3315 (NH); 1H NMR(CDCl3,
440 MHz, ppm); d 0.83 (s, 6H, CH3); 1.51 (m, 3H, 6a, 8a and 7e);
2.04 (m, 2H, 6e, 8e); 3.35 (m, 1H, 7a); 1.81 (s, 1H, NH); 3.91 (s,
2H, H-2, H-4); 7.26–7.47 (aromatic protons). 13C NMR (CDCl3,
400 MHz, ppm); d 20.71 (C-10, C-11); 36.73 (C-6, C-8); 21.41 (C-
7); 50.83 (C-1, C-5); 70.78 (C-2, C-4); 138.07 (ipso carbon);
217.07 (carbonyl), 128.26–138.07 (aromatic and ipso carbons).
3.3.5. Bis-(4-methyl)-2,4-diphenyl-1,5-
3.4. X-ray crystal structure of compound 1
dimethylazabicyclo[3.3.1]nonan-9-one (5)
IR(KBr, cmꢁ1); 1701 (carbonyl); 3314 (NH); 1H NMR(CDCl3,
440 MHz, ppm); d 0.82 (s, 6H, CH3); 1.47 (m, 3H, 6a, 8a and 7e);
2.10 (m, 2H, 6e, 8e); 3.46 (m, 1H, 7a); 1.80 (s, 1H, NH); 3.88 (s,
2H, H-2, H-4); 2.35 (s, 3H, CH3); d 7.15–7.42 (aromatic protons).
13C NMR (CDCl3, 400 MHz, ppm); d 20.80 (C-10, C-11); 36.93 (C-
6, C-8); 21.47 (C-7); 51.04 (C-1, C-5); 71.30 (C-2, C-4); 21.10 (p-
methyl); 218 (carbonyl), 128.64–137.38 (aromatic and ipso
carbons).
The crystal of compound 1 obtained by slow evaporation of eth-
anol solution at room temperature belong to the triclinic system,
space group P-1 with unit cell parameters a = 6.8950(5),
b = 1.5889(9), c = 11.9172(9),
a
= 76.2771(4), b = 78.000(3),
calc = 1.213 g/
l
= 0.073 mmꢁ1. All details of the measurements, crystal data
c
= 72.920(4), V = 874.41(12) Å3, Z = 2, T = 293 K,
q
cm3,
and structure refinement are given in Table 4. Selected bond length
(Å), bond angle (°) and torsional angles (°) are given in Table 5. The
bond length of O(1)AC(3) is 1.2146(14) Å and N(1)AH(1) bond dis-
tance is 0.912(15) Å. These bond lengths are similar to the standard
value. The bond angle of C(1)AC(2)AC(9) is 110.14(9)°,
C(5)AC(4)AC(10) is 110.13(99)° and torsional angle is ꢁ59° and
58° perceived by H(1a)AC(1)AC(2)AC(9) and C(10)AC(4)AC(5)
respectively, confirms that the two methyl group present at C-2
3.3.6. Bis-(3-bromo)-2,4-diphenyl-1,5-
dimethylazabicyclo[3.3.1]nonan-9-one (6)
IR(KBr, cmꢁ1); 1695 (carbonyl); 3292 (NH); 1H NMR(CDCl3,
440 MHz, ppm); d 0.84 (s, 6H, CH3); 1.52 (m, 3H, 6a, 8a and 7e);
2.10 (m, 2H, 6e, 8e); 3.32 (m, 1H, 7a); 1.87 (s, 1H, NH); 3.88 (s,

R. Venkateswaramoorthi et al. / Journal of Molecular Structure 1012 (2012) 119–125
123
Table 5
Selected bond length, bond angle and dihedral angle of compound 1.
0
Bond/valence angles (°)
Torsion/dihedral angles (°)
Bond lengths (AÅ)
O(1)AC(3) 1.2146(14)
N(1)AC(1) 1.4699(14)
N(1)AC(5) 1.4678(14)
C(1)AC(2) 1.5670(16)
C(1)AC(17) 1.5179(15)
C(2)AC(3) 1.5170(15
C(2)AC(8) 1.5509(15)
C(2)AC(9) 1.5260(17)
C(3)AC(4) 1.5213(15)
C(4)AC(5) 1.5669(16)
C(4)AC(6) 1.5489(16)
C(4)AC(10) 1.5258(17)
C(5)AC(11) 1.5147(15)
C(6)AC(7) 1.5274(17)
C(7)AC(8) 1.5263(16)
C(11)AC(12) 1.3907(16)
C(11)AC(16) 1.3925(16)
C(12)AC(13) 1.3900(18)
C(13)AC(14) 1.3787(19)
C(14)AC(15) 1.374(2)
C(1)AN(1)AC(5) 112.53(9)
N(1)AC(1)AC(2) 110.75(8)
N(1)AC(1)AC(17) 110.42(9)
C(2)AC(1)AC(17) 112.42(9)
C(1)AC(2)AC(3) 106.59(8)
O(1)AC(3)AC(2) 122.98(10)
O(1)AC(3)AC(4) 122.57(10)
C(2)AC(3)AC(4) 114.35(9)
C(3)AC(4)AC(5) 107.13(8)
C(3)AC(4)AC(6) 104.95(9)
C(3)AC(4)AC(10) 110.63(9)
C(5)AC(4)AC(6) 114.53(9)
C(5)AC(4)AC(10) 110.13(9)
C(6)AC(4)AC(10) 109.34(9)
N(1)AC(5)AC(4) 110.81(8)
C(6)AC(7)AC(8) 112.13(9)
C(2)AC(8)AC(7) 115.20(9)
C(5)AC(11)AC(12) 122.06(9)
C(5)AC(11)AC(16) 120.13(10)
C(12)AC(11)AC(16) 117.81(10)
C(3) C(2) C(8) H(8B) ꢁ69
C(9) C(2) C(8) H(8A) ꢁ66
C(9) C(2) C(8) H(8B) 50
C(1) C(2) C(9) H(9A) 49
C(1) C(2) C(9) H(9B) ꢁ72
C(1) C(2) C(9) H(9C) 169
C(3) C(2) C(9) H(9A) ꢁ69
C(3) C(2) C(9) H(9B) 171
C(3) C(2) C(9) H(9C) 51
C(8) C(2) C(9) H(9A) 176
C(8) C(2) C(9) H(9B) 56
C(8) C(2) C(9) H(9C) ꢁ64
C(3) C(4) C(5) H(5) ꢁ62
C(6) C(4) C(5) H(5) ꢁ178
C(10) C(4) C(5) H(5) 58
C(3) C(4) C(6) H(6A) 68
C(3) C(4) C(6) H(6B) ꢁ175
C(5) C(4) C(6) H(6A) ꢁ175
Fig. 3. Crystal structure of compound 1.
Fig. 4. Packing diagram of compound 1.

124
R. Venkateswaramoorthi et al. / Journal of Molecular Structure 1012 (2012) 119–125
Fig. 5. Optimized crystal structure of compound 1 by DFT studies.
Fig. 7. Boat form of piperidine ring of compound 1 by DFT studies.
angle of C2AC3AO24 is about 122.94° and C4AC3AO24 is about
122.37°. The nitrogen atom plays an important role in piperidine
molecule and its optimized bond angle is about 110.75°
(C2AC1AN23) and 110.81° (C4AC5AN23). In boat conformer, the
bond angle of CACAC is about 106.59° (C1AC2AC3) and 107.13°
(C3AC4AC5), by the X-ray diffraction. The chair conformer is ob-
tained at cyclohexane ring. Their corresponding dihedral angles
are about 111.65° (C6AC2AC3AO24) ꢁ111.37° (O24AC3AC4AC6).
The experimental value of dihedral angle the above mentioned
compound was 115.07 and ꢁ113.27°. Optimized crystal structure
is given in Fig. 5. Experimental and theoretical bond length, bond
angle and dihedral angle of compound 1 are given Table S3 (see
Supplementary data).
3.6. Conformational analysis
In order to understand the conformational analysis of piperi-
dine and cyclohexane rings, vicinal coupling constants are more
important parameter. Compound 1 is not giving NOE correlation
with axial position of the benzylic protons at C-1 and C-5. This
shows that, two methyl groups present at C-1 and C-5 are occupy-
ing equatorial orientations. Single crystal X-ray analysis and DFT
theoretical calculation shows that in the target molecule piperidine
ring adopting with boat confirmation and cyclohexane ring adopt-
ing with chair confirmation and are given in Fig. 6 and Fig. 7,
respectively.
Fig. 6. Chair form of cyclohexane ring of compound 1 by DFT studies.
and C-4 position in crystal structure is in an equatorial orientation.
Single crystal XRD studies revealed that the cyclohexane moiety
exhibits chair confirmation and piperidine moiety exhibits in boat
conformation. The crystal structure of compound 1 given in Fig. 3
and packing pattern of molecule in the crystal lattice is given in
Fig. 4. This packing pattern shows that compound 1 is stabilized
by intermolecular NAH...O hydrogen bonding.
4. Conclusion
Conformation of compound 1 was carried out using HOMO-
COSY, HSQC and NOESY correlation spectral data and DFT calcula-
tions using B3LYP/6-31 G (d,p) level of basis set. This X-ray
crystallographic and DFT calculation results shows that the com-
pound 1 exist in boat (piperidine ring) and chair (cyclohexane ring)
conformation with equatorial orientations of the phenyl ring and
bridged methyl group. The results obtained from one dimentional,
two dimensional NMR spectra, mass spectra and DFT calculation
3.5. Optimization geometry
The optimized parameters such as bond lengths, bond angles
and dihedral angles were calculated using B3LYP/6-31 G (d,p) level
basis set. The theoretical studies shows that, our representative
compound 1 existing boat conformation with piperidine moiety
and chair conformation with respect to cyclohexane moiety. The

R. Venkateswaramoorthi et al. / Journal of Molecular Structure 1012 (2012) 119–125
125
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Acknowledgements
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Appendix A. Supplementary material
The deposition number CCDC 826898 for Compound 1 contains
the supplementary crystallographic data for this paper. These data
can be obtained free of charge via www.ccdc.cam.ac.uk/data_re-
quest/cif or Cambridge crystallographic Data Centre, 12, Union
Road, Cambridge CB2 1EZ, UK; fax: +44 1223 336033. HOMOCOSY,
HSQC and NOESY are attached S1, S2 and S3, respectively. Experi-
mental FT-IR and theoretical FT-IR and FT-Raman spectra are at-
tached Fig. S1, Fig. S2, Fig. S3 and Fig. S4, respectively.
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