10,11-Dihydro­carbamazepine–acetic acid (1/1)

Johnston, A.; Florence, A.J.; Fernandes, P.; Shankland, N.; Kennedy, A.R.

doi:10.1107/S1600536806044369

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 62| Part 12| December 2006| Pages o5361-o5362

https://doi.org/10.1107/S1600536806044369

10,11-Dihydrocarbamazepine–acetic acid (1/1)

Andrea Johnston,^a Alastair J. Florence,^a ^* Philippe Fernandes,^a Norman Shankland ^a and Alan R. Kennedy ^b

^aSolid-State Research Group, Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow G4 0NR, Scotland, and ^bWestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, Scotland
^*Correspondence e-mail: alastair.florence@strath.ac.uk

(Received 12 October 2006; accepted 24 October 2006; online 3 November 2006)

In the title compound [systematic name: 10,11-dihydro-5H-dibenz[b,f]azepine-5-carboxamide–ethanoic acid (1/1)], C₁₅H₁₄N₂O·C₂H₄O₂, the dihydrocarbamazepine and acetic acid molecules are hydrogen bonded to form an R²₂(8) motif, which is further connected into a centrosymmetric double motif arrangement.

Comment

10,11-Dihydrocarbamazepine (DHC) is a recognized impurity in carbamazepine (CBZ), a dibenzazepine drug used to control seizures (Cyr et al., 1987 ). DHC is known to crystallize in three polymorphic forms: monoclinic form I (Bandoli et al., 1992 ), orthorhombic form II (Harrison et al., 2006 ) and triclinic form III (Leech et al., 2006 ). The title compound, (I), was produced during an automated parallel crystallization study (Florence, Johnston, Fernandes et al., 2006 ) of DHC as part of a wider study into the predicted and experimental structures of CBZ (Florence, Johnston, Price et al., 2006 ; Florence, Leech et al., 2006 ). The sample was identified as a new form using multi-sample foil transmission X-ray powder diffraction analysis (Florence et al., 2003 ). Subsequent manual recrystallization from a saturated acetic acid solution by slow evaporation at 298 K yielded single crystals of (I) suitable for X-ray diffraction.

The crystal structure of (I) is essentially isostructural with that of CBZ–acetic acid (1/1) (Fleischman et al., 2003 ). Accordingly, it displays the same space group with very similar unit-cell parameters and packing arrangements. Specifically, the DHC and acetic acid molecules are connected via O2—H1⋯O1 and N2—H2N⋯O3 hydrogen bonds (Table 1) to form an R₂²(8) (Etter, 1990 ) dimer motif (Fig. 1). A third hydrogen bond, N2—H1N⋯O3ⁱ [symmetry code (i) 1 − x, 1 − y, −z], joins adjacent dimers to form a centrosymmetric double motif arrangement (Fig. 2).

Figure 1
The asymmetric unit of (I)

, showing 50% probability displacement ellipsoids. Hydrogen bonds are shown as dashed lines.

Figure 2
The hydrogen bonded R₂²(8) motifs of (I)

joined in a centrosymmetric arrangement via an R₄²(8) motif. Hydrogen bonds are shown as dashed lines. [Symmetry code: (b) 1 − x, 1 − y, −z.]

Experimental

Crystals of (I) were grown from a saturated acetic acid solution of 10,11-dihydrocarbamazepine by isothermal solvent evaporation at 298 K.

Crystal data

C₁₅H₁₄N₂O·C₂H₄O₂
M_r = 298.33
Monoclinic, P 2₁ /c
a = 5.3104 (4) Å
b = 15.4246 (17) Å
c = 18.732 (2) Å
β = 95.106 (7)°
V = 1528.3 (3) Å³
Z = 4
D_x = 1.297 Mg m⁻³
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 123 (2) K
Needle, colourless
0.35 × 0.08 × 0.04 mm

Data collection

Nonius KappaCCD area-detector diffractometer
φ and ω scans
Absorption correction: none
10078 measured reflections
2652 independent reflections
1605 reflections with I > 2σ(I)
R_int = 0.103
θ_max = 25.0°

Refinement

Refinement on F²
R[F² > 2σ(F²)] = 0.076
wR(F²) = 0.147
S = 1.13
2652 reflections
212 parameters
H atoms treated by a mixture of independent and constrained refinement
w = 1/[σ²(F_o²) + (0.0421P)² + 0.9028P] where P = (F_o² + 2F_c²)/3
(Δ/σ)_max < 0.001
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H1⋯O1	1.03 (4)	1.53 (4)	2.547 (3)	167 (4)
N2—H1N⋯O3ⁱ	0.88 (4)	2.20 (3)	2.894 (4)	136 (3)
N2—H2N⋯O3	0.95 (4)	2.04 (4)	2.970 (4)	164 (4)
Symmetry code: (i) -x+1, -y+1, -z.

H atoms bonded to N and O were located in difference maps and refined isotropically (distances are given in Table 1). All other H atoms were positioned geometrically and treated as riding with C—H = 0.95–0.99 Å, and with U_iso(H) = 1.2U_eq(C), or U_iso(H) = 1.5U_eq(C) for the methyl group.

Data collection: COLLECT (Hooft, 1988 ) and DENZO (Otwinowski & Minor, 1997 ); cell refinement: DENZO and COLLECT; data reduction: DENZO; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536806044369/ob2091sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536806044369/ob2091Isup2.hkl

Computing details top

Data collection: COLLECT (Hooft, 1988) and DENZO (Otwinowski & Minor, 1997); cell refinement: DENZO and COLLECT; data reduction: DENZO; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.

10,11-dihydro-5H- dibenz[b,f]azepine-5-carboxamide–ethanoic acid (1/1) top

Crystal data top

C₁₅H₁₄N₂O·C₂H₄O₂	F(000) = 632
M_r = 298.33	D_x = 1.297 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 5.3104 (4) Å	Cell parameters from 2544 reflections
b = 15.4246 (17) Å	θ = 1.0–25.0°
c = 18.732 (2) Å	µ = 0.09 mm⁻¹
β = 95.106 (7)°	T = 123 K
V = 1528.3 (3) Å³	Needle, colourless
Z = 4	0.35 × 0.08 × 0.04 mm

Data collection top

Nonius KappaCCD area-detector diffractometer	1605 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.103
Graphite monochromator	θ_max = 25.0°, θ_min = 3.4°
φ and ω scans	h = −6→6
10078 measured reflections	k = −18→18
2652 independent reflections	l = −22→22

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.076	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.147	H atoms treated by a mixture of independent and constrained refinement
S = 1.13	w = 1/[σ²(F_o²) + (0.0421P)² + 0.9028P] where P = (F_o² + 2F_c²)/3
2652 reflections	(Δ/σ)_max < 0.001
212 parameters	Δρ_max = 0.20 e Å⁻³
0 restraints	Δρ_min = −0.21 e Å⁻³

Special details top

Experimental. Crystals desolvate on removal from solvent. Crystals shatter on contact with the cold-stream, data collected from shattered remains of a large needle.

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 (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.8377 (4)	0.34174 (15)	0.13207 (12)	0.0352 (6)
N1	0.9605 (5)	0.27153 (17)	0.03492 (13)	0.0269 (7)
N2	0.7442 (6)	0.4022 (2)	0.02286 (18)	0.0389 (8)
C1	0.9582 (6)	0.2604 (2)	−0.04138 (17)	0.0283 (8)
C2	1.1325 (6)	0.3027 (2)	−0.07952 (18)	0.0338 (9)
H2	1.2500	0.3420	−0.0560	0.041*
C3	1.1349 (7)	0.2874 (2)	−0.15231 (19)	0.0396 (10)
H3	1.2547	0.3163	−0.1787	0.047*
C4	0.9643 (7)	0.2305 (2)	−0.18686 (19)	0.0401 (10)
H4	0.9675	0.2199	−0.2367	0.048*
C5	0.7880 (7)	0.1887 (2)	−0.14856 (18)	0.0381 (9)
H5	0.6695	0.1501	−0.1727	0.046*
C6	0.7827 (6)	0.2026 (2)	−0.07482 (17)	0.0300 (8)
C7	0.6026 (6)	0.1580 (2)	−0.02990 (18)	0.0359 (9)
H7A	0.4707	0.1288	−0.0620	0.043*
H7B	0.5179	0.2023	−0.0022	0.043*
C8	0.7257 (6)	0.0909 (2)	0.02226 (18)	0.0323 (9)
H8A	0.5933	0.0687	0.0515	0.039*
H8B	0.7807	0.0416	−0.0064	0.039*
C9	0.9487 (6)	0.1180 (2)	0.07306 (17)	0.0293 (8)
C10	1.0615 (7)	0.0537 (2)	0.11878 (18)	0.0339 (9)
H10	0.9928	−0.0032	0.1161	0.041*
C11	1.2663 (7)	0.0695 (2)	0.16708 (18)	0.0359 (9)
H11	1.3361	0.0243	0.1971	0.043*
C12	1.3711 (6)	0.1524 (2)	0.17175 (17)	0.0348 (9)
H12	1.5137	0.1642	0.2046	0.042*
C13	1.2646 (6)	0.2175 (2)	0.12785 (17)	0.0318 (9)
H13	1.3346	0.2742	0.1307	0.038*
C14	1.0568 (6)	0.2006 (2)	0.07973 (17)	0.0259 (8)
C15	0.8450 (6)	0.3395 (2)	0.06550 (18)	0.0302 (8)
O2	0.5016 (5)	0.41693 (15)	0.19878 (12)	0.0353 (6)
O3	0.4298 (5)	0.51232 (18)	0.10996 (14)	0.0588 (8)
C16	0.3724 (7)	0.4812 (2)	0.1662 (2)	0.0378 (9)
C17	0.1550 (7)	0.5111 (2)	0.2049 (2)	0.0425 (10)
H17A	0.1996	0.5655	0.2300	0.064*
H17B	0.1148	0.4670	0.2398	0.064*
H17C	0.0077	0.5206	0.1704	0.064*
H1N	0.748 (6)	0.405 (2)	−0.0237 (19)	0.034 (10)*
H2N	0.651 (7)	0.446 (3)	0.045 (2)	0.054 (12)*
H1	0.639 (7)	0.394 (3)	0.168 (2)	0.069 (13)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0502 (16)	0.0310 (14)	0.0239 (14)	0.0104 (12)	0.0007 (11)	−0.0023 (11)
N1	0.0389 (17)	0.0192 (15)	0.0227 (16)	0.0021 (13)	0.0026 (13)	−0.0008 (12)
N2	0.060 (2)	0.0302 (18)	0.0265 (19)	0.0166 (16)	0.0036 (16)	0.0037 (15)
C1	0.032 (2)	0.0286 (19)	0.025 (2)	0.0085 (16)	0.0036 (16)	−0.0005 (15)
C2	0.041 (2)	0.0265 (19)	0.034 (2)	0.0043 (17)	0.0023 (17)	0.0041 (16)
C3	0.049 (2)	0.036 (2)	0.036 (2)	0.0054 (19)	0.0129 (19)	0.0094 (18)
C4	0.060 (3)	0.037 (2)	0.023 (2)	0.013 (2)	0.0055 (19)	−0.0003 (18)
C5	0.054 (3)	0.030 (2)	0.028 (2)	0.0061 (18)	−0.0047 (18)	−0.0022 (17)
C6	0.036 (2)	0.027 (2)	0.026 (2)	0.0050 (16)	−0.0037 (16)	−0.0007 (15)
C7	0.039 (2)	0.033 (2)	0.035 (2)	−0.0004 (17)	−0.0015 (17)	−0.0048 (17)
C8	0.037 (2)	0.028 (2)	0.033 (2)	−0.0027 (16)	0.0076 (16)	−0.0039 (16)
C9	0.037 (2)	0.030 (2)	0.0217 (18)	−0.0002 (17)	0.0110 (16)	−0.0035 (15)
C10	0.049 (2)	0.025 (2)	0.029 (2)	−0.0012 (17)	0.0092 (18)	−0.0013 (16)
C11	0.047 (2)	0.035 (2)	0.026 (2)	0.0090 (19)	0.0043 (17)	0.0059 (17)
C12	0.037 (2)	0.042 (2)	0.0250 (19)	0.0036 (18)	0.0008 (16)	−0.0018 (18)
C13	0.042 (2)	0.0252 (19)	0.029 (2)	0.0006 (17)	0.0040 (17)	−0.0022 (16)
C14	0.031 (2)	0.0233 (19)	0.0239 (18)	0.0027 (15)	0.0064 (15)	0.0007 (15)
C15	0.039 (2)	0.0253 (19)	0.026 (2)	−0.0005 (17)	0.0006 (16)	−0.0044 (17)
O2	0.0461 (16)	0.0282 (14)	0.0317 (14)	0.0075 (12)	0.0035 (12)	0.0018 (12)
O3	0.089 (2)	0.0520 (19)	0.0378 (17)	0.0340 (16)	0.0187 (15)	0.0141 (14)
C16	0.050 (2)	0.030 (2)	0.032 (2)	0.0059 (19)	−0.0056 (18)	−0.0054 (18)
C17	0.048 (2)	0.034 (2)	0.045 (2)	0.0091 (19)	0.0025 (19)	−0.0023 (19)

Geometric parameters (Å, º) top

O1—C15	1.252 (4)	C8—C9	1.510 (4)
N1—C15	1.366 (4)	C8—H8A	0.9900
N1—C1	1.439 (4)	C8—H8B	0.9900
N1—C14	1.445 (4)	C9—C14	1.398 (4)
N2—C15	1.335 (4)	C9—C10	1.409 (5)
N2—H1N	0.88 (3)	C10—C11	1.373 (5)
N2—H2N	0.95 (4)	C10—H10	0.9500
C1—C2	1.383 (4)	C11—C12	1.395 (5)
C1—C6	1.397 (4)	C11—H11	0.9500
C2—C3	1.385 (5)	C12—C13	1.385 (5)
C2—H2	0.9500	C12—H12	0.9500
C3—C4	1.381 (5)	C13—C14	1.386 (4)
C3—H3	0.9500	C13—H13	0.9500
C4—C5	1.388 (5)	O2—C16	1.324 (4)
C4—H4	0.9500	O2—H1	1.03 (4)
C5—C6	1.401 (5)	O3—C16	1.221 (4)
C5—H5	0.9500	C16—C17	1.489 (5)
C6—C7	1.497 (5)	C17—H17A	0.9800
C7—C8	1.530 (5)	C17—H17B	0.9800
C7—H7A	0.9900	C17—H17C	0.9800
C7—H7B	0.9900

C15—N1—C1	122.9 (3)	C7—C8—H8B	107.6
C15—N1—C14	119.1 (3)	H8A—C8—H8B	107.0
C1—N1—C14	117.3 (3)	C14—C9—C10	116.0 (3)
C15—N2—H1N	126 (2)	C14—C9—C8	127.0 (3)
C15—N2—H2N	117 (2)	C10—C9—C8	117.1 (3)
H1N—N2—H2N	117 (3)	C11—C10—C9	123.0 (3)
C2—C1—C6	121.3 (3)	C11—C10—H10	118.5
C2—C1—N1	120.7 (3)	C9—C10—H10	118.5
C6—C1—N1	117.9 (3)	C10—C11—C12	119.5 (3)
C1—C2—C3	119.6 (3)	C10—C11—H11	120.2
C1—C2—H2	120.2	C12—C11—H11	120.2
C3—C2—H2	120.2	C13—C12—C11	119.2 (3)
C4—C3—C2	120.5 (3)	C13—C12—H12	120.4
C4—C3—H3	119.8	C11—C12—H12	120.4
C2—C3—H3	119.8	C12—C13—C14	120.6 (3)
C3—C4—C5	119.9 (3)	C12—C13—H13	119.7
C3—C4—H4	120.1	C14—C13—H13	119.7
C5—C4—H4	120.1	C13—C14—C9	121.8 (3)
C4—C5—C6	120.8 (3)	C13—C14—N1	117.1 (3)
C4—C5—H5	119.6	C9—C14—N1	121.1 (3)
C6—C5—H5	119.6	O1—C15—N2	122.0 (3)
C1—C6—C5	118.0 (3)	O1—C15—N1	119.6 (3)
C1—C6—C7	118.4 (3)	N2—C15—N1	118.4 (3)
C5—C6—C7	123.6 (3)	C16—O2—H1	111 (2)
C6—C7—C8	114.3 (3)	O3—C16—O2	122.2 (3)
C6—C7—H7A	108.7	O3—C16—C17	124.2 (3)
C8—C7—H7A	108.7	O2—C16—C17	113.6 (3)
C6—C7—H7B	108.7	C16—C17—H17A	109.5
C8—C7—H7B	108.7	C16—C17—H17B	109.5
H7A—C7—H7B	107.6	H17A—C17—H17B	109.5
C9—C8—C7	118.8 (3)	C16—C17—H17C	109.5
C9—C8—H8A	107.6	H17A—C17—H17C	109.5
C7—C8—H8A	107.6	H17B—C17—H17C	109.5
C9—C8—H8B	107.6

C15—N1—C1—C2	83.9 (4)	C14—C9—C10—C11	−0.4 (5)
C14—N1—C1—C2	−105.5 (3)	C8—C9—C10—C11	179.5 (3)
C15—N1—C1—C6	−99.1 (4)	C9—C10—C11—C12	−0.3 (5)
C14—N1—C1—C6	71.4 (4)	C10—C11—C12—C13	0.5 (5)
C6—C1—C2—C3	−0.3 (5)	C11—C12—C13—C14	−0.1 (5)
N1—C1—C2—C3	176.6 (3)	C12—C13—C14—C9	−0.6 (5)
C1—C2—C3—C4	0.1 (5)	C12—C13—C14—N1	−178.8 (3)
C2—C3—C4—C5	0.4 (5)	C10—C9—C14—C13	0.8 (5)
C3—C4—C5—C6	−0.8 (5)	C8—C9—C14—C13	−179.0 (3)
C2—C1—C6—C5	−0.1 (5)	C10—C9—C14—N1	178.9 (3)
N1—C1—C6—C5	−177.1 (3)	C8—C9—C14—N1	−0.9 (5)
C2—C1—C6—C7	178.9 (3)	C15—N1—C14—C13	−69.1 (4)
N1—C1—C6—C7	2.0 (4)	C1—N1—C14—C13	120.0 (3)
C4—C5—C6—C1	0.7 (5)	C15—N1—C14—C9	112.7 (4)
C4—C5—C6—C7	−178.3 (3)	C1—N1—C14—C9	−58.2 (4)
C1—C6—C7—C8	−69.5 (4)	C1—N1—C15—O1	174.6 (3)
C5—C6—C7—C8	109.5 (4)	C14—N1—C15—O1	4.2 (5)
C6—C7—C8—C9	53.4 (4)	C1—N1—C15—N2	−5.8 (5)
C7—C8—C9—C14	1.7 (5)	C14—N1—C15—N2	−176.2 (3)
C7—C8—C9—C10	−178.2 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H1···O1	1.03 (4)	1.53 (4)	2.547 (3)	167 (4)
N2—H1N···O3ⁱ	0.88 (4)	2.20 (3)	2.894 (4)	136 (3)
N2—H2N···O3	0.95 (4)	2.04 (4)	2.970 (4)	164 (4)

Symmetry code: (i) −x+1, −y+1, −z.

Acknowledgements

The authors thank the Basic Technology Programme of the UK Research Councils for funding this work under the project Control and Prediction of the Organic Solid State (https://www.cposs.org.uk).

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