organic compounds
Chlordiazepoxide dichloromethane monosolvate
aDivision of Applied Physical Chemistry, School of Chemical Science and Engineering, 100 44 Stockholm, Sweden
*Correspondence e-mail: afischer@kth.se
In the title compound (systematic name: 7-chloro-2-methylamino-5-phenyl-3H-1,4-benzodiazepine 4-oxide dichloromethane monosolvate), C16H14ClN3O·CH2Cl2, the seven-membered ring adopts a boat conformation with the CH2 group as the prow and the two aromatic C atoms as the stern. The dihedral angle between the benzene rings is 75.25 (6)°. The features centrosymmetric pairs of chlordiazepoxide molecules linked by pairs of N—H⋯O hydrogen bonds, which generate R22(12) loops.
Related literature
For the synthesis of chlordiazepoxide, see: Sternbach et al. (1961). For the structure of chlordiazepoxide, see: Bertolasi et al. (1982). For the structure of a second polymorph of chlordiazepoxide, see: Singh et al. (1998). For the structure of chlordiazepoxide hydrochloride, see: Herrnstadt et al. (1979). For the early history of benzopdiazepines, see: Sternbach (1979).
Experimental
Crystal data
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Refinement
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Data collection: COLLECT (Nonius, 1999); cell DIRAX (Duisenberg, 1992); data reduction: EVALCCD (Duisenberg et al., 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2007).; software used to prepare material for publication: publCIF (Westrip, 2010).
Supporting information
10.1107/S1600536812009695/hb6668sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812009695/hb6668Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536812009695/hb6668Isup3.cml
Chlordiazepoxide was synthesized according to the procedure described by Sternbach et al.(1961), starting from commercial 2-amino-5-chlorobenzophenone. Slow evaporation of the solution of the final product in dichloromethane yielded colourless, block-shaped crystals of the title compound. Once removed from the mother liquor, the crystals decomposed slowly (within days), yielding solvent-free chlordiazepoxide.
All H atoms except that attached to N were placed at calculated positions and refined riding. The N–H atom was located from the Fourier map and refined with the N–H distance restrained to 0.88 (2) Å.
Chlordiazepozide (7-chloro-2-methylamino-5-phenyl-3H-1,4-benzodiazepine 4-oxide) was the first benzodiazepine to enter the market as member of a new class of powerful tranquilizers. The
of the hydrochloride was determined in 1979 (Herrnstadt et al., 1979), the structure of the pure compound in 1982 (Bertolasi et al., 1982). The reason for the study of chlordiazepoxide salts was the presence of three potential protonation sites (Herrnstadt et al. 1979). In order to study a number of different chlordiazepoxide salts, we synthesized the compound according to the description by Sternbach et al. (1961). The final step in this synthesis is the crystallization from dichloromethane. It turned out that the crystallization product that forms initially is a chlordiazepoxide dichloromethane solvate, whose structure is described here. The title compound (Fig. 1) features pairs of chlordiazepoxide molecules, which are hydrogen-bonded via two symmetry-equivalent N–H···O bonds across an inversion centre (Fig. 2). The same pattern could be found in the hydrochloride (Herrnstadt et al., 1979). In the structure of pure chlordiazepoxide, pairs of molecules of the same (due to the high energy barrier of ring inversion, benzodiazepines are chiral) were observed and it was argued that this arrangement might be more stable than dimers of two different enantiomers. However, this effect must be quite subtle since the only interactions between the chlordiazepoxide and dichloromethane molecules are due to The dihedral angle between the two phenyl groups is 75.25 (6)°.For the synthesis of chlordiazepoxide, see: Sternbach et al. (1961). For the structure of chlordiazepoxide, see: Bertolasi et al. (1982). For the structure of a second polymorph of chlordiazepoxide, see: Singh et al. (1998). For the structure of chlordiazepoxide hydrochloride, see: Herrnstadt et al. (1979). For the early history of benzopdiazepines, see: Sternbach (1979).
Data collection: COLLECT (Nonius, 1999); cell
DIRAX (Duisenberg, 1992); data reduction: EVALCCD (Duisenberg et al., 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2007).; software used to prepare material for publication: publCIF (Westrip, 2010).C16H14ClN3O·CH2Cl2 | Z = 2 |
Mr = 384.69 | F(000) = 396 |
Triclinic, P1 | Dx = 1.443 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.8310 (12) Å | Cell parameters from 38 reflections |
b = 9.461 (2) Å | θ = 8.7–19.5° |
c = 12.6947 (5) Å | µ = 0.53 mm−1 |
α = 94.284 (11)° | T = 173 K |
β = 93.821 (9)° | Plate, colourless |
γ = 108.499 (13)° | 0.60 × 0.33 × 0.04 mm |
V = 885.4 (2) Å3 |
Bruker–Nonius KappaCCD diffractometer | 4040 independent reflections |
Radiation source: fine-focus sealed tube | 3124 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.034 |
φ&ω scans | θmax = 27.5°, θmin = 4.5° |
Absorption correction: multi-scan SADABS (Sheldrick, 2003) | h = −10→10 |
Tmin = 0.763, Tmax = 0.979 | k = −12→12 |
20348 measured reflections | l = −15→16 |
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)] = 0.040 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.104 | w = 1/[σ2(Fo2) + (0.0409P)2 + 0.7625P] where P = (Fo2 + 2Fc2)/3 |
S = 1.03 | (Δ/σ)max < 0.001 |
4040 reflections | Δρmax = 0.76 e Å−3 |
221 parameters | Δρmin = −0.52 e Å−3 |
1 restraint |
C16H14ClN3O·CH2Cl2 | γ = 108.499 (13)° |
Mr = 384.69 | V = 885.4 (2) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.8310 (12) Å | Mo Kα radiation |
b = 9.461 (2) Å | µ = 0.53 mm−1 |
c = 12.6947 (5) Å | T = 173 K |
α = 94.284 (11)° | 0.60 × 0.33 × 0.04 mm |
β = 93.821 (9)° |
Bruker–Nonius KappaCCD diffractometer | 4040 independent reflections |
Absorption correction: multi-scan SADABS (Sheldrick, 2003) | 3124 reflections with I > 2σ(I) |
Tmin = 0.763, Tmax = 0.979 | Rint = 0.034 |
20348 measured reflections |
R[F2 > 2σ(F2)] = 0.040 | 1 restraint |
wR(F2) = 0.104 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.03 | Δρmax = 0.76 e Å−3 |
4040 reflections | Δρmin = −0.52 e Å−3 |
221 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.4054 (3) | 0.0142 (2) | 0.68015 (14) | 0.0228 (4) | |
C2 | 0.4147 (3) | −0.1283 (2) | 0.67919 (15) | 0.0233 (4) | |
C3 | 0.3620 (3) | −0.2137 (2) | 0.76314 (15) | 0.0229 (4) | |
C4 | 0.3110 (2) | −0.1489 (2) | 0.85106 (14) | 0.0219 (4) | |
C5 | 0.3146 (2) | 0.00119 (19) | 0.85985 (14) | 0.0183 (3) | |
C6 | 0.3543 (2) | 0.08072 (19) | 0.76981 (14) | 0.0188 (4) | |
C7 | 0.3392 (2) | 0.23116 (19) | 0.76213 (14) | 0.0193 (4) | |
C8 | 0.2418 (3) | 0.2605 (2) | 0.66676 (14) | 0.0213 (4) | |
C9 | 0.3090 (3) | 0.3890 (2) | 0.61483 (15) | 0.0251 (4) | |
C10 | 0.2113 (3) | 0.4097 (2) | 0.52552 (16) | 0.0335 (5) | |
C11 | 0.0461 (3) | 0.3048 (3) | 0.48835 (17) | 0.0375 (5) | |
C12 | −0.0217 (3) | 0.1780 (3) | 0.53961 (18) | 0.0374 (5) | |
C13 | 0.0762 (3) | 0.1547 (2) | 0.62793 (16) | 0.0300 (4) | |
C14 | 0.4974 (2) | 0.2983 (2) | 0.93612 (13) | 0.0189 (4) | |
C15 | 0.3509 (2) | 0.1940 (2) | 0.99178 (13) | 0.0186 (4) | |
C16 | 0.1763 (3) | 0.1635 (2) | 1.14472 (17) | 0.0334 (5) | |
C17 | 0.0152 (4) | 0.5580 (3) | 0.1687 (3) | 0.0561 (7) | |
Cl1 | 0.50033 (8) | −0.20239 (6) | 0.57295 (4) | 0.03756 (16) | |
Cl2 | 0.04988 (9) | 0.72192 (8) | 0.10404 (6) | 0.0542 (2) | |
Cl3 | 0.19167 (10) | 0.57040 (9) | 0.26233 (6) | 0.0620 (2) | |
O1 | 0.39853 (18) | 0.47104 (13) | 0.84472 (10) | 0.0218 (3) | |
N1 | 0.4092 (2) | 0.33547 (16) | 0.84073 (11) | 0.0176 (3) | |
N2 | 0.2700 (2) | 0.05504 (17) | 0.95575 (12) | 0.0203 (3) | |
N3 | 0.3075 (2) | 0.25397 (18) | 1.08078 (12) | 0.0227 (3) | |
H1 | 0.4336 | 0.0679 | 0.6199 | 0.027* | |
H3 | 0.3613 | −0.3145 | 0.7599 | 0.027* | |
H4 | 0.2720 | −0.2076 | 0.9078 | 0.026* | |
H9 | 0.4214 | 0.4621 | 0.6407 | 0.030* | |
H10 | 0.2581 | 0.4963 | 0.4896 | 0.040* | |
H11 | −0.0206 | 0.3202 | 0.4275 | 0.045* | |
H12 | −0.1357 | 0.1066 | 0.5144 | 0.045* | |
H13 | 0.0303 | 0.0662 | 0.6621 | 0.036* | |
H14A | 0.5617 | 0.3906 | 0.9836 | 0.023* | |
H14B | 0.5862 | 0.2490 | 0.9159 | 0.023* | |
H16A | 0.0613 | 0.1156 | 1.1011 | 0.050* | |
H16B | 0.1578 | 0.2274 | 1.2043 | 0.050* | |
H16C | 0.2211 | 0.0863 | 1.1720 | 0.050* | |
H17A | −0.0980 | 0.5380 | 0.2038 | 0.067* | |
H17B | 0.0001 | 0.4723 | 0.1151 | 0.067* | |
H3A | 0.379 (3) | 0.3395 (19) | 1.1074 (17) | 0.027* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0312 (10) | 0.0182 (9) | 0.0194 (9) | 0.0079 (8) | 0.0027 (7) | 0.0051 (7) |
C2 | 0.0296 (10) | 0.0209 (9) | 0.0205 (9) | 0.0104 (8) | 0.0026 (7) | 0.0002 (7) |
C3 | 0.0275 (10) | 0.0175 (9) | 0.0247 (9) | 0.0094 (8) | −0.0012 (8) | 0.0030 (7) |
C4 | 0.0233 (9) | 0.0206 (9) | 0.0214 (9) | 0.0059 (7) | 0.0006 (7) | 0.0067 (7) |
C5 | 0.0156 (8) | 0.0184 (8) | 0.0192 (8) | 0.0037 (7) | −0.0011 (7) | 0.0015 (6) |
C6 | 0.0206 (9) | 0.0148 (8) | 0.0200 (9) | 0.0049 (7) | −0.0020 (7) | 0.0013 (6) |
C7 | 0.0209 (9) | 0.0169 (8) | 0.0197 (9) | 0.0055 (7) | 0.0009 (7) | 0.0028 (6) |
C8 | 0.0288 (10) | 0.0192 (9) | 0.0178 (9) | 0.0117 (8) | −0.0014 (7) | −0.0008 (7) |
C9 | 0.0343 (11) | 0.0206 (9) | 0.0209 (9) | 0.0100 (8) | 0.0001 (8) | 0.0017 (7) |
C10 | 0.0522 (14) | 0.0285 (10) | 0.0247 (10) | 0.0199 (10) | −0.0009 (9) | 0.0070 (8) |
C11 | 0.0535 (15) | 0.0380 (12) | 0.0262 (11) | 0.0260 (11) | −0.0128 (10) | 0.0004 (9) |
C12 | 0.0385 (13) | 0.0344 (12) | 0.0349 (12) | 0.0114 (10) | −0.0164 (10) | −0.0044 (9) |
C13 | 0.0361 (12) | 0.0227 (10) | 0.0292 (10) | 0.0087 (9) | −0.0062 (9) | 0.0024 (8) |
C14 | 0.0175 (9) | 0.0201 (9) | 0.0175 (8) | 0.0044 (7) | −0.0028 (7) | 0.0023 (7) |
C15 | 0.0166 (8) | 0.0221 (9) | 0.0165 (8) | 0.0058 (7) | −0.0015 (7) | 0.0038 (7) |
C16 | 0.0309 (11) | 0.0362 (11) | 0.0273 (11) | 0.0018 (9) | 0.0105 (9) | −0.0007 (8) |
C17 | 0.0338 (14) | 0.0492 (15) | 0.085 (2) | 0.0101 (12) | 0.0003 (13) | 0.0207 (14) |
Cl1 | 0.0618 (4) | 0.0276 (3) | 0.0305 (3) | 0.0216 (2) | 0.0185 (2) | 0.00376 (19) |
Cl2 | 0.0412 (3) | 0.0717 (5) | 0.0646 (4) | 0.0315 (3) | 0.0154 (3) | 0.0322 (3) |
Cl3 | 0.0553 (4) | 0.0777 (5) | 0.0559 (4) | 0.0205 (4) | 0.0033 (3) | 0.0317 (4) |
O1 | 0.0268 (7) | 0.0131 (6) | 0.0243 (7) | 0.0060 (5) | −0.0019 (5) | −0.0003 (5) |
N1 | 0.0189 (7) | 0.0153 (7) | 0.0183 (7) | 0.0051 (6) | 0.0001 (6) | 0.0026 (5) |
N2 | 0.0203 (8) | 0.0206 (8) | 0.0185 (7) | 0.0048 (6) | 0.0013 (6) | 0.0018 (6) |
N3 | 0.0214 (8) | 0.0231 (8) | 0.0203 (8) | 0.0036 (7) | 0.0013 (6) | −0.0015 (6) |
C1—C2 | 1.372 (3) | C16—N3 | 1.451 (3) |
C1—C6 | 1.402 (2) | C17—Cl3 | 1.730 (3) |
C2—C3 | 1.391 (3) | C17—Cl2 | 1.762 (3) |
C2—Cl1 | 1.7428 (19) | O1—N1 | 1.3090 (18) |
C3—C4 | 1.376 (3) | C1—H1 | 0.9500 |
C4—C5 | 1.407 (2) | C3—H3 | 0.9500 |
C5—N2 | 1.393 (2) | C4—H4 | 0.9500 |
C5—C6 | 1.413 (2) | C9—H9 | 0.9500 |
C6—C7 | 1.475 (2) | C10—H10 | 0.9500 |
C7—N1 | 1.306 (2) | C11—H11 | 0.9500 |
C7—C8 | 1.478 (2) | C12—H12 | 0.9500 |
C8—C13 | 1.394 (3) | C13—H13 | 0.9500 |
C8—C9 | 1.396 (3) | C14—H14A | 0.9900 |
C9—C10 | 1.386 (3) | C14—H14B | 0.9900 |
C10—C11 | 1.384 (3) | C16—H16A | 0.9800 |
C11—C12 | 1.380 (3) | C16—H16B | 0.9800 |
C12—C13 | 1.387 (3) | C16—H16C | 0.9800 |
C14—N1 | 1.474 (2) | C17—H17A | 0.9900 |
C14—C15 | 1.511 (2) | C17—H17B | 0.9900 |
C15—N2 | 1.297 (2) | N3—H3A | 0.854 (16) |
C15—N3 | 1.338 (2) | ||
C2—C1—C6 | 120.20 (16) | C6—C1—H1 | 119.9 |
C1—C2—C3 | 121.22 (17) | C4—C3—H3 | 120.7 |
C1—C2—Cl1 | 119.68 (14) | C2—C3—H3 | 120.7 |
C3—C2—Cl1 | 119.07 (14) | C3—C4—H4 | 118.8 |
C4—C3—C2 | 118.55 (16) | C5—C4—H4 | 118.8 |
C3—C4—C5 | 122.33 (16) | C10—C9—H9 | 120.1 |
N2—C5—C4 | 116.32 (15) | C8—C9—H9 | 120.1 |
N2—C5—C6 | 126.13 (16) | C11—C10—H10 | 119.8 |
C4—C5—C6 | 117.48 (16) | C9—C10—H10 | 119.8 |
C1—C6—C5 | 119.75 (16) | C12—C11—H11 | 120.0 |
C1—C6—C7 | 116.61 (15) | C10—C11—H11 | 120.0 |
C5—C6—C7 | 123.60 (16) | C11—C12—H12 | 120.0 |
N1—C7—C6 | 119.34 (16) | C13—C12—H12 | 120.0 |
N1—C7—C8 | 121.14 (15) | C12—C13—H13 | 119.8 |
C6—C7—C8 | 119.51 (15) | C8—C13—H13 | 119.8 |
C13—C8—C9 | 119.24 (17) | N1—C14—H14A | 110.2 |
C13—C8—C7 | 118.08 (16) | C15—C14—H14A | 110.2 |
C9—C8—C7 | 122.68 (17) | N1—C14—H14B | 110.2 |
C10—C9—C8 | 119.88 (19) | C15—C14—H14B | 110.2 |
C11—C10—C9 | 120.4 (2) | H14A—C14—H14B | 108.5 |
C12—C11—C10 | 120.04 (19) | N3—C16—H16A | 109.5 |
C11—C12—C13 | 120.1 (2) | N3—C16—H16B | 109.5 |
C12—C13—C8 | 120.31 (19) | H16A—C16—H16B | 109.5 |
N1—C14—C15 | 107.42 (14) | N3—C16—H16C | 109.5 |
N2—C15—N3 | 121.51 (16) | H16A—C16—H16C | 109.5 |
N2—C15—C14 | 122.57 (16) | H16B—C16—H16C | 109.5 |
N3—C15—C14 | 115.91 (16) | Cl3—C17—H17A | 109.0 |
Cl3—C17—Cl2 | 112.88 (15) | Cl2—C17—H17A | 109.0 |
C7—N1—O1 | 124.88 (15) | Cl3—C17—H17B | 109.0 |
C7—N1—C14 | 118.94 (14) | Cl2—C17—H17B | 109.0 |
O1—N1—C14 | 116.05 (13) | H17A—C17—H17B | 107.8 |
C15—N2—C5 | 118.83 (15) | C15—N3—H3A | 117.0 (15) |
C15—N3—C16 | 121.24 (16) | C16—N3—H3A | 119.7 (15) |
C2—C1—H1 | 119.9 |
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3A···O1i | 0.85 (2) | 2.08 (2) | 2.916 (2) | 166 (2) |
Symmetry code: (i) −x+1, −y+1, −z+2. |
Experimental details
Crystal data | |
Chemical formula | C16H14ClN3O·CH2Cl2 |
Mr | 384.69 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 173 |
a, b, c (Å) | 7.8310 (12), 9.461 (2), 12.6947 (5) |
α, β, γ (°) | 94.284 (11), 93.821 (9), 108.499 (13) |
V (Å3) | 885.4 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.53 |
Crystal size (mm) | 0.60 × 0.33 × 0.04 |
Data collection | |
Diffractometer | Bruker–Nonius KappaCCD |
Absorption correction | Multi-scan SADABS (Sheldrick, 2003) |
Tmin, Tmax | 0.763, 0.979 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 20348, 4040, 3124 |
Rint | 0.034 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.104, 1.03 |
No. of reflections | 4040 |
No. of parameters | 221 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.76, −0.52 |
Computer programs: COLLECT (Nonius, 1999), DIRAX (Duisenberg, 1992), EVALCCD (Duisenberg et al., 2003), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2007)., publCIF (Westrip, 2010).
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3A···O1i | 0.854 (16) | 2.080 (17) | 2.916 (2) | 166 (2) |
Symmetry code: (i) −x+1, −y+1, −z+2. |
Acknowledgements
The Swedish Research Council is acknowledged for providing funding for the single-crystal diffractometer.
References
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Chlordiazepozide (7-chloro-2-methylamino-5-phenyl-3H-1,4-benzodiazepine 4-oxide) was the first benzodiazepine to enter the market as member of a new class of powerful tranquilizers. The crystal structure of the hydrochloride was determined in 1979 (Herrnstadt et al., 1979), the structure of the pure compound in 1982 (Bertolasi et al., 1982). The reason for the study of chlordiazepoxide salts was the presence of three potential protonation sites (Herrnstadt et al. 1979). In order to study a number of different chlordiazepoxide salts, we synthesized the compound according to the description by Sternbach et al. (1961). The final step in this synthesis is the crystallization from dichloromethane. It turned out that the crystallization product that forms initially is a chlordiazepoxide dichloromethane solvate, whose structure is described here. The title compound (Fig. 1) features pairs of chlordiazepoxide molecules, which are hydrogen-bonded via two symmetry-equivalent N–H···O bonds across an inversion centre (Fig. 2). The same pattern could be found in the hydrochloride (Herrnstadt et al., 1979). In the structure of pure chlordiazepoxide, pairs of molecules of the same chirality (due to the high energy barrier of ring inversion, benzodiazepines are chiral) were observed and it was argued that this arrangement might be more stable than dimers of two different enantiomers. However, this effect must be quite subtle since the only interactions between the chlordiazepoxide and dichloromethane molecules are due to van der Waals forces. The dihedral angle between the two phenyl groups is 75.25 (6)°.