2,4-Bis(2-bromo­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one

In the mol­ecular structure of the title compound, C₂₀H₁₉Br₂NO, the fused six-membered heterocyclic and cyclo­hexane rings adopt a twin-chair conformation with equatorial orientations of all the substituents. Both the ortho-bromo substituents of the benzene rings are oriented towards the carbonyl group; the dihedral angle between the ring planes is 29.13 (3)°. In the crystal structure, the N-H group does not participate in any hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.027
• wR factor = 0.060
• Data-to-parameter ratio = 18.5

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low .......       0.93

Author Response: The crytal diffracted weakly at high angles even though the data was collected upto 0.75 \%A resolution. We had made several attempts of data collection but this was the best.

Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR) is > 1.10
            Tmin and Tmax reported:      0.232     0.297
            Tmin and Tmax expected:      0.141     0.201
            RR =      1.112
            Please check that your absorption correction is appropriate.
            Value of measurement temperature given =   298.000
            Value of melting point given =     0.000
REFLT03_ALERT_3_C  Reflection count < 95% complete
           From the CIF: _diffrn_reflns_theta_max           28.30
           From the CIF: _diffrn_reflns_theta_full          28.30
           From the CIF: _reflns_number_total               4098
           TEST2: Reflns within _diffrn_reflns_theta_max
           Count of symmetry unique reflns         4417
           Completeness (_total/calc)             92.78%
PLAT420_ALERT_2_C D-H Without Acceptor       N1     -   H1A    ...          ?
PLAT060_ALERT_4_C Ratio Tmax/Tmin (Exp-to-Rep) (too) Large .......       1.13
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.68
PLAT153_ALERT_1_C The su's on the Cell Axes   are Equal (x 100000)         30 Ang.

Alert level G
ABSTM02_ALERT_3_G  When printed, the submitted absorption T values will be
            replaced by the scaled T values. Since the ratio of scaled T's
            is identical to the ratio of reported T values, the scaling
            does not imply a change to the absorption corrections used in
            the study.
            Ratio of Tmax expected/reported      0.678
            Tmax scaled      0.201 Tmin scaled      0.157
PLAT793_ALERT_4_G The Model has Chirality at C1      (Verify) ....          S
PLAT793_ALERT_4_G The Model has Chirality at C2      (Verify) ....          S
PLAT793_ALERT_4_G The Model has Chirality at C6      (Verify) ....          R
PLAT793_ALERT_4_G The Model has Chirality at C7      (Verify) ....          R

   1 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   6 ALERT level C = Check and explain
   5 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   6 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

---

S1. Comment

3-Azabicyclononan-9-ones are important class of compounds due to their significance as bio-active molecules (Jeyaraman & Avila, 1981; Barker et al., 2005).

The title compound, (I), exists in a chair–chair conformation with equatorial orientations of the ortho bromo-phenyl groups on each side of the secondary amino group with the torsion angles of C8—C2—C1—C9 and C8—C6—C7—C15 being 177.88 (4) and 179.42 (6)°, respectively. In both aryl groups, the bromo substituents point towards the carbonyl group and the dihedral angle between the ring planes is 29.13 (3)°. The piperidine ring adopts near ideal chair conformation with the deviation of ring atoms N1 and C8 from the C1/C2/C6/C7 plane by -0.635 (3)and 0.705 (3)Å, respectively, Q_T = 0.599 (2)Å, q(2)=0.047 (2)Å, q(3)=0.597 (2)Å, θ = 4.71 (19)° Cremer & Pople, 1975; Web & Becker, 1967), whereas the cyclohexane ring atoms C4 and C8 deviate from the C2/C3/C5/C6 plane by -0.539 (4) and 0.725 (3)Å, respectively, Q_T = 0.565 (2)Å, q(2)=0.141 (2)Å, q(3)=0.548 (2)Å, θ = 14.4 (2)°, indicating a deviation from the ideal chair conformation of the cyclohexane part in the title compound. The crystal structure is stabilized by the intermolecular van der Waals interactions.

Related literature

For 3-azabicyclononan-9-ones and their significance as bio-active molecules, see: Barker et al. (2005); Jeyaraman & Avila (1981). For puckering parameters, see: Cremer & Pople (1975); Web & Becker (1967). For a similiar structure see; Parthiban et al. (2008).

S2. Experimental

A mixture of cyclohexanone (0.05 mol) and ortho bromobenzaldehyde (0.1 mol) was added to a warm solution of ammonium acetate (0.075 mol) in 50 ml of absolute ethanol. The mixture was gently warmed on a hot plate until a yellow colour was formed and then cooled to room temperature. Then, 50 ml of ether was added and allowed to stir over night at room temperature. At the end, the crude azabicyclic ketone was separated by filtration and washed with 1:5 v/v ethanol–ether mixture till the solid became colourless. Recrystallization of the compound from acetone gave colourless blocks of (I).

S3. Refinement

The nitrogen-bound H atom was located in a difference map and refined isotropically. The other hydrogen atoms were fixed geometrically (C—H = 0.93–0.98Å) and refined as riding with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

Fig. 1. The molecular structure of (I) with non-hydrogen atoms represented as 30% probability ellipsoids.

2,4-Bis(2-bromophenyl)-3-azabicyclo[3.3.1]nonan-9-one

Crystal data

C20H19Br2NO	Z = 2
Mr = 449.18	F(000) = 448
Triclinic, P1	Dx = 1.684 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.8389 (3) Å	Cell parameters from 5642 reflections
b = 10.5770 (3) Å	θ = 2.5–28.2°
c = 11.0274 (3) Å	µ = 4.58 mm^−1
α = 101.099 (2)°	T = 298 K
β = 93.725 (2)°	Block, colourless
γ = 97.399 (1)°	0.45 × 0.38 × 0.35 mm
V = 885.94 (5) Å^3

Data collection

Bruker APEXII CCD diffractometer	4098 independent reflections
Radiation source: fine-focus sealed tube	3266 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.017
ω scans	θmax = 28.3°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 1999)	h = −10→10
Tmin = 0.232, Tmax = 0.297	k = −13→13
10959 measured reflections	l = −14→14

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.027	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.060	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0207P)^2 + 0.5638P] where P = (Fo^2 + 2Fc^2)/3
4098 reflections	(Δ/σ)max = 0.002
221 parameters	Δρmax = 0.58 e Å^−3
0 restraints	Δρmin = −0.56 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)

are estimated using the full covariance matrix. The cell e.s.d.'s are taken

into account individually in the estimation of e.s.d.'s in distances, angles

and torsion angles; correlations between e.s.d.'s in cell parameters are only

used when they are defined by crystal symmetry. An approximate (isotropic)

treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and

goodness of fit S are based on F², conventional R-factors R are based

on F, with F set to zero for negative F². The threshold expression of

F² > σ(F²) is used only for calculating R-factors(gt) etc. and is

not relevant to the choice of reflections for refinement. R-factors based

on F² are statistically about twice as large as those based on F, and R-

factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br1	−0.00438 (3)	0.47719 (2)	0.77681 (2)	0.05065 (8)
Br2	0.16949 (3)	1.23193 (3)	1.01448 (2)	0.06070 (9)
C1	0.2124 (2)	0.74756 (18)	0.75331 (18)	0.0301 (4)
H1	0.1437	0.7370	0.8228	0.036*
C2	0.0889 (2)	0.76537 (19)	0.64395 (19)	0.0344 (4)
H2	−0.0049	0.6918	0.6254	0.041*
C3	0.1735 (3)	0.7773 (2)	0.5238 (2)	0.0428 (5)
H3A	0.2294	0.7011	0.4980	0.051*
H3B	0.0839	0.7778	0.4591	0.051*
C4	0.3064 (3)	0.8987 (2)	0.5360 (2)	0.0432 (5)
H4A	0.4119	0.8865	0.5806	0.052*
H4B	0.3333	0.9102	0.4539	0.052*
C5	0.2434 (3)	1.0214 (2)	0.60396 (19)	0.0392 (5)
H5A	0.1647	1.0500	0.5468	0.047*
H5B	0.3418	1.0895	0.6280	0.047*
C6	0.1515 (2)	1.00528 (19)	0.72040 (18)	0.0331 (4)
H6	0.0967	1.0828	0.7479	0.040*
C7	0.2692 (2)	0.98341 (18)	0.83118 (17)	0.0294 (4)
H7	0.1987	0.9747	0.9001	0.035*
C8	0.0132 (2)	0.8886 (2)	0.68529 (18)	0.0342 (4)
C9	0.3014 (2)	0.62834 (18)	0.72007 (17)	0.0304 (4)
C10	0.4692 (3)	0.6383 (2)	0.6847 (2)	0.0389 (5)
H10	0.5265	0.7194	0.6796	0.047*
C11	0.5525 (3)	0.5302 (2)	0.6570 (2)	0.0495 (6)
H11	0.6641	0.5392	0.6328	0.059*
C12	0.4711 (3)	0.4095 (2)	0.6651 (2)	0.0556 (6)
H12	0.5280	0.3371	0.6472	0.067*
C13	0.3055 (3)	0.3958 (2)	0.6995 (2)	0.0482 (6)
H13	0.2496	0.3142	0.7047	0.058*
C14	0.2228 (3)	0.50413 (19)	0.72632 (19)	0.0350 (4)
C15	0.4125 (2)	1.09742 (18)	0.87430 (17)	0.0290 (4)
C16	0.3860 (3)	1.21258 (19)	0.95107 (18)	0.0337 (4)
C17	0.5159 (3)	1.3181 (2)	0.9863 (2)	0.0436 (5)
H17	0.4946	1.3938	1.0380	0.052*
C18	0.6757 (3)	1.3104 (2)	0.9446 (2)	0.0499 (6)
H18	0.7629	1.3812	0.9670	0.060*
C19	0.7071 (3)	1.1976 (2)	0.8696 (2)	0.0482 (6)
H19	0.8161	1.1920	0.8421	0.058*
C20	0.5772 (3)	1.0923 (2)	0.8347 (2)	0.0381 (5)
H20	0.6003	1.0166	0.7839	0.046*
N1	0.3422 (2)	0.86343 (15)	0.79409 (16)	0.0304 (4)
O1	−0.13950 (19)	0.89419 (17)	0.68681 (16)	0.0521 (4)
H1A	0.407 (3)	0.851 (2)	0.850 (2)	0.040 (7)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.04366 (13)	0.03775 (13)	0.06740 (17)	−0.00469 (9)	0.01281 (11)	0.00737 (11)
Br2	0.05389 (15)	0.06429 (18)	0.05949 (17)	0.02181 (12)	0.01497 (12)	−0.01039 (13)
C1	0.0296 (9)	0.0256 (10)	0.0349 (10)	0.0042 (7)	0.0038 (8)	0.0056 (8)
C2	0.0286 (9)	0.0300 (10)	0.0415 (11)	0.0019 (8)	−0.0038 (8)	0.0035 (9)
C3	0.0511 (13)	0.0398 (12)	0.0351 (11)	0.0125 (10)	−0.0022 (10)	−0.0001 (9)
C4	0.0505 (13)	0.0492 (13)	0.0325 (11)	0.0104 (10)	0.0097 (9)	0.0107 (10)
C5	0.0441 (11)	0.0369 (12)	0.0386 (12)	0.0063 (9)	−0.0008 (9)	0.0138 (9)
C6	0.0326 (10)	0.0299 (10)	0.0371 (11)	0.0102 (8)	0.0012 (8)	0.0046 (8)
C7	0.0300 (9)	0.0276 (10)	0.0302 (10)	0.0044 (7)	0.0033 (7)	0.0049 (8)
C8	0.0310 (9)	0.0405 (12)	0.0327 (11)	0.0088 (8)	−0.0003 (8)	0.0100 (9)
C9	0.0335 (9)	0.0278 (10)	0.0295 (10)	0.0060 (8)	0.0003 (8)	0.0046 (8)
C10	0.0357 (10)	0.0380 (12)	0.0448 (12)	0.0081 (9)	0.0059 (9)	0.0104 (9)
C11	0.0417 (12)	0.0553 (15)	0.0575 (15)	0.0220 (11)	0.0123 (11)	0.0135 (12)
C12	0.0657 (16)	0.0446 (14)	0.0637 (16)	0.0311 (12)	0.0140 (13)	0.0109 (12)
C13	0.0608 (15)	0.0297 (12)	0.0551 (14)	0.0101 (10)	0.0065 (11)	0.0083 (10)
C14	0.0371 (10)	0.0304 (10)	0.0362 (11)	0.0041 (8)	0.0025 (8)	0.0038 (8)
C15	0.0314 (9)	0.0280 (10)	0.0284 (10)	0.0053 (8)	0.0005 (7)	0.0079 (8)
C16	0.0403 (10)	0.0322 (11)	0.0297 (10)	0.0100 (8)	0.0010 (8)	0.0062 (8)
C17	0.0646 (15)	0.0278 (11)	0.0353 (12)	0.0034 (10)	−0.0054 (10)	0.0047 (9)
C18	0.0547 (14)	0.0427 (13)	0.0455 (13)	−0.0154 (11)	−0.0072 (11)	0.0108 (11)
C19	0.0346 (11)	0.0573 (15)	0.0500 (14)	−0.0043 (10)	0.0028 (10)	0.0117 (12)
C20	0.0337 (10)	0.0375 (11)	0.0411 (12)	0.0048 (9)	0.0047 (9)	0.0029 (9)
N1	0.0292 (8)	0.0249 (8)	0.0362 (9)	0.0055 (6)	−0.0050 (7)	0.0053 (7)
O1	0.0292 (7)	0.0588 (11)	0.0693 (11)	0.0119 (7)	0.0028 (7)	0.0120 (9)

Geometric parameters (Å, º)

Br1—C14	1.903 (2)	C7—H7	0.9800
Br2—C16	1.897 (2)	C8—O1	1.207 (2)
C1—N1	1.465 (2)	C9—C10	1.393 (3)
C1—C9	1.515 (3)	C9—C14	1.394 (3)
C1—C2	1.552 (3)	C10—C11	1.382 (3)
C1—H1	0.9800	C10—H10	0.9300
C2—C8	1.505 (3)	C11—C12	1.373 (4)
C2—C3	1.539 (3)	C11—H11	0.9300
C2—H2	0.9800	C12—C13	1.373 (3)
C3—C4	1.524 (3)	C12—H12	0.9300
C3—H3A	0.9700	C13—C14	1.381 (3)
C3—H3B	0.9700	C13—H13	0.9300
C4—C5	1.525 (3)	C15—C20	1.393 (3)
C4—H4A	0.9700	C15—C16	1.391 (3)
C4—H4B	0.9700	C16—C17	1.387 (3)
C5—C6	1.539 (3)	C17—C18	1.369 (3)
C5—H5A	0.9700	C17—H17	0.9300
C5—H5B	0.9700	C18—C19	1.375 (4)
C6—C8	1.506 (3)	C18—H18	0.9300
C6—C7	1.554 (3)	C19—C20	1.385 (3)
C6—H6	0.9800	C19—H19	0.9300
C7—N1	1.457 (2)	C20—H20	0.9300
C7—C15	1.518 (2)	N1—H1A	0.81 (2)
N1—C1—C9	109.63 (15)	O1—C8—C2	124.48 (19)
N1—C1—C2	110.38 (16)	O1—C8—C6	123.98 (19)
C9—C1—C2	112.32 (16)	C2—C8—C6	111.51 (16)
N1—C1—H1	108.1	C10—C9—C14	116.51 (18)
C9—C1—H1	108.1	C10—C9—C1	121.26 (17)
C2—C1—H1	108.1	C14—C9—C1	122.21 (17)
C8—C2—C3	107.21 (17)	C11—C10—C9	121.5 (2)
C8—C2—C1	107.83 (16)	C11—C10—H10	119.3
C3—C2—C1	115.42 (16)	C9—C10—H10	119.3
C8—C2—H2	108.7	C12—C11—C10	120.3 (2)
C3—C2—H2	108.7	C12—C11—H11	119.9
C1—C2—H2	108.7	C10—C11—H11	119.9
C4—C3—C2	114.03 (17)	C13—C12—C11	119.9 (2)
C4—C3—H3A	108.7	C13—C12—H12	120.1
C2—C3—H3A	108.7	C11—C12—H12	120.1
C4—C3—H3B	108.7	C12—C13—C14	119.5 (2)
C2—C3—H3B	108.7	C12—C13—H13	120.3
H3A—C3—H3B	107.6	C14—C13—H13	120.3
C5—C4—C3	112.67 (18)	C13—C14—C9	122.3 (2)
C5—C4—H4A	109.1	C13—C14—Br1	116.76 (16)
C3—C4—H4A	109.1	C9—C14—Br1	120.89 (15)
C5—C4—H4B	109.1	C20—C15—C16	116.80 (18)
C3—C4—H4B	109.1	C20—C15—C7	120.81 (17)
H4A—C4—H4B	107.8	C16—C15—C7	122.36 (17)
C4—C5—C6	114.82 (17)	C17—C16—C15	122.0 (2)
C4—C5—H5A	108.6	C17—C16—Br2	116.64 (16)
C6—C5—H5A	108.6	C15—C16—Br2	121.32 (15)
C4—C5—H5B	108.6	C18—C17—C16	119.7 (2)
C6—C5—H5B	108.6	C18—C17—H17	120.2
H5A—C5—H5B	107.5	C16—C17—H17	120.2
C8—C6—C5	108.13 (16)	C17—C18—C19	119.9 (2)
C8—C6—C7	107.18 (16)	C17—C18—H18	120.0
C5—C6—C7	115.25 (16)	C19—C18—H18	120.0
C8—C6—H6	108.7	C18—C19—C20	120.3 (2)
C5—C6—H6	108.7	C18—C19—H19	119.9
C7—C6—H6	108.7	C20—C19—H19	119.9
N1—C7—C15	110.21 (15)	C19—C20—C15	121.3 (2)
N1—C7—C6	109.31 (15)	C19—C20—H20	119.3
C15—C7—C6	111.09 (15)	C15—C20—H20	119.3
N1—C7—H7	108.7	C7—N1—C1	113.89 (15)
C15—C7—H7	108.7	C7—N1—H1A	111.0 (16)
C6—C7—H7	108.7	C1—N1—H1A	108.6 (16)
N1—C1—C2—C8	−55.2 (2)	C9—C10—C11—C12	−0.6 (4)
C9—C1—C2—C8	−177.89 (16)	C10—C11—C12—C13	0.7 (4)
N1—C1—C2—C3	64.6 (2)	C11—C12—C13—C14	−0.3 (4)
C9—C1—C2—C3	−58.1 (2)	C12—C13—C14—C9	−0.2 (3)
C8—C2—C3—C4	55.1 (2)	C12—C13—C14—Br1	−178.65 (19)
C1—C2—C3—C4	−65.0 (2)	C10—C9—C14—C13	0.2 (3)
C2—C3—C4—C5	−45.4 (3)	C1—C9—C14—C13	−178.10 (19)
C3—C4—C5—C6	43.4 (3)	C10—C9—C14—Br1	178.65 (15)
C4—C5—C6—C8	−51.3 (2)	C1—C9—C14—Br1	0.3 (3)
C4—C5—C6—C7	68.6 (2)	N1—C7—C15—C20	23.6 (2)
C8—C6—C7—N1	58.74 (19)	C6—C7—C15—C20	−97.7 (2)
C5—C6—C7—N1	−61.6 (2)	N1—C7—C15—C16	−158.48 (18)
C8—C6—C7—C15	−179.43 (15)	C6—C7—C15—C16	80.2 (2)
C5—C6—C7—C15	60.2 (2)	C20—C15—C16—C17	0.5 (3)
C3—C2—C8—O1	113.0 (2)	C7—C15—C16—C17	−177.53 (18)
C1—C2—C8—O1	−122.1 (2)	C20—C15—C16—Br2	−178.76 (15)
C3—C2—C8—C6	−64.9 (2)	C7—C15—C16—Br2	3.2 (3)
C1—C2—C8—C6	59.9 (2)	C15—C16—C17—C18	0.3 (3)
C5—C6—C8—O1	−114.9 (2)	Br2—C16—C17—C18	179.52 (17)
C7—C6—C8—O1	120.3 (2)	C16—C17—C18—C19	−0.9 (3)
C5—C6—C8—C2	63.1 (2)	C17—C18—C19—C20	0.8 (4)
C7—C6—C8—C2	−61.7 (2)	C18—C19—C20—C15	0.0 (3)
N1—C1—C9—C10	−24.4 (3)	C16—C15—C20—C19	−0.6 (3)
C2—C1—C9—C10	98.7 (2)	C7—C15—C20—C19	177.4 (2)
N1—C1—C9—C14	153.82 (18)	C15—C7—N1—C1	178.86 (15)
C2—C1—C9—C14	−83.1 (2)	C6—C7—N1—C1	−58.8 (2)
C14—C9—C10—C11	0.2 (3)	C9—C1—N1—C7	−178.59 (16)
C1—C9—C10—C11	178.5 (2)	C2—C1—N1—C7	57.2 (2)