organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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2-Chloro-1-(2,4,4-tri­methyl-2,3,4,5-tetra­hydro-1H-1,5-benzodiazepin-1-yl)ethanone

aCentre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India, and bDepartment of Chemistry, Government Arts College (Autonomous), Coimbatore 641 018, India
*Correspondence e-mail: mnpsy2004@yahoo.com

(Received 1 April 2013; accepted 6 May 2013; online 11 May 2013)

In the title compound, C14H19ClN2O, the diazepine ring adopts a boat conformation. The Cl atom of the chloro­acetyl group is trans to the N atom of the diazepine ring. In the crystal, the mol­ecules form chains running along the diagonal of the ac plane through N—H⋯O hydrogen bonds.

Related literature

For the biological activity of benzodiazepine derivatives, see: Ponnuswamy et al. (2006[Ponnuswamy, S., Murugadoss, R., Jeyaraman, R., Thiruvalluvar, A. & Parthasarathi, V. (2006). Indian J. Chem. Sect. B, 45, 2059-2070.]); Rahbaek et al. (1999[Rahbaek, L., Breinholt, J., Frisvad, J. C. & Christophersen, C. (1999). J. Org. Chem. 64, 1689-1692.]). For related structures see: Thiruvalluvar & Ponnuswamy (2007[Thiruvalluvar, A. & Ponnuswamy, S. (2007). Acta Cryst. E63, o4264.]); Kavitha et al. (2012[Kavitha, T., Ponnuswamy, S., Suguna, S., Sakthivel, P. & Ponnuswamy, M. N. (2012). Mol. Cryst. Liq. Cryst. 557, 18-27.]). For puckering parameters, see: Cremer & Pople (1975[Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.]) and for asymmetry parameters, see: Nardelli (1983[Nardelli, M. (1983). Acta Cryst. C39, 1141-1142.]). For bond-length data, see: Allen et al. (1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2 pp. 1-19.]).

[Scheme 1]

Experimental

Crystal data
  • C14H19ClN2O

  • Mr = 266.76

  • Monoclinic, P 21 /n

  • a = 10.3971 (3) Å

  • b = 12.2589 (3) Å

  • c = 11.0994 (3) Å

  • β = 93.953 (1)°

  • V = 1411.33 (7) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.26 mm−1

  • T = 293 K

  • 0.23 × 0.22 × 0.20 mm

Data collection
  • Bruker SMART APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2008[Bruker (2008). APEX2, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.942, Tmax = 0.949

  • 13339 measured reflections

  • 3568 independent reflections

  • 2767 reflections with I > 2σ(I)

  • Rint = 0.018

Refinement
  • R[F2 > 2σ(F2)] = 0.040

  • wR(F2) = 0.120

  • S = 1.07

  • 3568 reflections

  • 167 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.22 e Å−3

  • Δρmin = −0.27 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯O1i 0.835 (19) 2.276 (19) 3.1049 (16) 171.5 (17)
Symmetry code: (i) [x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2008[Bruker (2008). APEX2, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2008[Bruker (2008). APEX2, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

Various substituted 1,5-benzodiazepines have been synthesized and their stereochemistry has been reported (Ponnuswamy et al., 2006). Among these, the benzodiazepines act as a class of psychoactive drugs. Benzodiazepines are known for their natural occurrence in filamentous fungi and actinomycetes of the genera pencillium, aspergillus and streptomyces (Rahbaek et al., 1999). Benzodiazepines from aspergillus include asperlicin, which is used for the treatment of gastrointestinal and central nervous system disorders. Against this background and to ascertain the molecular structure and conformation, the X-ray crystal structure determination of the title compound has been carried out.

The ORTEP plot of the molecule is shown in Fig. 1. The chloro substituted benzodiazepine derivative crystallizes in the monoclinic space group P21/n. The diazepine ring system adopts a boat conformation (Kavitha et al., 2012). The puckering parameters (Cremer & Pople, 1975) and the asymmetry parameters (Nardelli, 1983) are: q2=0.9558 (2) Å, q3 = 0.1431 (2) Å, ϕ2 = 16.93 (9)° and Δs(C6)= 25.13 (2)°. The Cl atom of the chloroacetyl group is trans to the N atom of the diazepine ring which is evidenced from the torsion angle [N5—C15—C16—CL1=]-157.5 (1)°. The bond lengths C16—CL1 and C15—O1 [1.770 (2) Å & 1.219 (2) Å] are comparable with the mean value reported in the literature (Allen et al., 1987). The carbonyl group is oriented anti to C6 [C6—N5—C15—O1=] 169.7 (2)° and syn to C4 [C4—N5—C15—O1=] -5.12 (2)°. The crystal packing shows that the molecules form linear chains linked through N—H···O hydrogen bonds. The chains run along the diagonal of the ac plane (Fig. 2).

Related literature top

For the biological activity of benzodiazepine derivatives, see: Ponnuswamy et al. (2006); Rahbaek et al. (1999). For related structures see: Thiruvalluvar & Ponnuswamy (2007); Kavitha et al. (2012). For puckering parameters, see: Cremer & Pople (1975) and for asymmetry parameters, see: Nardelli (1983). For bond-length data, see: Allen et al. (1987).

Experimental top

To an ice cold solution of tetrahydrobenzodiazepine (1.9 g, 10 m.mol) in anhydrous benzene (50 ml), triethylamine (4 ml, 30 m.mol) and chloroacetylchloride (2.4 ml, 30 m.mol) were added and stirred at room temperature. The resulting solid was purified by recrystallization from benzene to yield pale yellow crystals.

Refinement top

The H atom bonded to N was freely refined. C-bound H atoms were positioned geometrically (C–H = 0.93–0.98 Å) and allowed to ride on their parent atoms, with Uiso(H) = 1.5Ueq(C) for methyl H atoms and 1.2Ueq(C) for all other H atoms.

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing the atomic numbering and displacement ellipsoids drawn at 50% probability level.
[Figure 2] Fig. 2. The crystal packing of the molecules. H atoms not involved in hydrogen bonding (dashed lines) have been omitted for clarity.
2-Chloro-1-(2,4,4-trimethyl-2,3,4,5-tetrahydro-1H-1,5-benzodiazepin-1-yl)ethanone top
Crystal data top
C14H19ClN2OF(000) = 568
Mr = 266.76Dx = 1.255 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 3568 reflections
a = 10.3971 (3) Åθ = 2.5–28.5°
b = 12.2589 (3) ŵ = 0.26 mm1
c = 11.0994 (3) ÅT = 293 K
β = 93.953 (1)°Block, pale yellow
V = 1411.33 (7) Å30.23 × 0.22 × 0.20 mm
Z = 4
Data collection top
Bruker SMART APEXII CCD
diffractometer
3568 independent reflections
Radiation source: fine-focus sealed tube2767 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.018
ω and ϕ scansθmax = 28.5°, θmin = 2.5°
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
h = 1113
Tmin = 0.942, Tmax = 0.949k = 1614
13339 measured reflectionsl = 1414
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.040Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.120H atoms treated by a mixture of independent and constrained refinement
S = 1.07 w = 1/[σ2(Fo2) + (0.0584P)2 + 0.253P]
where P = (Fo2 + 2Fc2)/3
3568 reflections(Δ/σ)max < 0.001
167 parametersΔρmax = 0.22 e Å3
0 restraintsΔρmin = 0.27 e Å3
Crystal data top
C14H19ClN2OV = 1411.33 (7) Å3
Mr = 266.76Z = 4
Monoclinic, P21/nMo Kα radiation
a = 10.3971 (3) ŵ = 0.26 mm1
b = 12.2589 (3) ÅT = 293 K
c = 11.0994 (3) Å0.23 × 0.22 × 0.20 mm
β = 93.953 (1)°
Data collection top
Bruker SMART APEXII CCD
diffractometer
3568 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
2767 reflections with I > 2σ(I)
Tmin = 0.942, Tmax = 0.949Rint = 0.018
13339 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0400 restraints
wR(F2) = 0.120H atoms treated by a mixture of independent and constrained refinement
S = 1.07Δρmax = 0.22 e Å3
3568 reflectionsΔρmin = 0.27 e Å3
167 parameters
Special details top

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
xyzUiso*/Ueq
C20.51697 (13)0.25960 (11)0.45502 (13)0.0430 (3)
C30.42704 (13)0.16143 (11)0.43872 (12)0.0418 (3)
H3A0.47030.09890.47670.050*
H3B0.35110.17590.48220.050*
C40.38266 (12)0.12997 (12)0.31006 (12)0.0421 (3)
H40.32970.18970.27510.051*
C60.61213 (12)0.07242 (11)0.29286 (11)0.0378 (3)
C70.65316 (15)0.02988 (12)0.25761 (13)0.0472 (3)
H70.59980.07200.20550.057*
C80.77192 (16)0.06946 (13)0.29912 (15)0.0557 (4)
H80.79950.13770.27490.067*
C90.84918 (16)0.00669 (15)0.37691 (16)0.0584 (4)
H90.93110.03140.40260.070*
C100.80708 (14)0.09221 (13)0.41727 (13)0.0490 (3)
H100.86000.13210.47200.059*
C110.68638 (12)0.13399 (11)0.37769 (11)0.0373 (3)
C120.5320 (2)0.28786 (16)0.58975 (16)0.0687 (5)
H12A0.56500.22570.63440.103*
H12B0.44960.30780.61710.103*
H12C0.59080.34780.60210.103*
C130.46332 (16)0.35866 (13)0.38470 (19)0.0635 (5)
H13A0.52170.41890.39700.095*
H13B0.38100.37800.41270.095*
H13C0.45350.34130.30020.095*
C140.30135 (17)0.02757 (15)0.30537 (17)0.0618 (4)
H14A0.27490.01080.22290.093*
H14B0.22650.03890.34990.093*
H14C0.35100.03190.34040.093*
C150.48304 (13)0.14054 (13)0.11892 (12)0.0449 (3)
C160.60674 (15)0.13616 (16)0.05310 (14)0.0554 (4)
H16A0.62530.06110.03270.067*
H16B0.67800.16330.10570.067*
N10.64710 (12)0.23518 (10)0.41521 (12)0.0446 (3)
H10.7043 (18)0.2675 (14)0.4580 (16)0.057 (5)*
N50.49529 (10)0.11740 (9)0.23764 (9)0.0394 (3)
O10.38003 (10)0.16453 (13)0.06665 (10)0.0683 (4)
Cl10.59194 (4)0.21546 (4)0.07992 (4)0.06677 (17)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C20.0408 (7)0.0429 (7)0.0454 (7)0.0064 (6)0.0046 (6)0.0003 (6)
C30.0388 (7)0.0465 (7)0.0405 (7)0.0047 (6)0.0059 (5)0.0050 (5)
C40.0304 (6)0.0524 (8)0.0436 (7)0.0024 (6)0.0021 (5)0.0048 (6)
C60.0312 (6)0.0460 (7)0.0359 (6)0.0047 (5)0.0011 (5)0.0016 (5)
C70.0464 (8)0.0492 (8)0.0458 (7)0.0031 (6)0.0013 (6)0.0063 (6)
C80.0541 (9)0.0532 (8)0.0599 (9)0.0185 (7)0.0053 (7)0.0055 (7)
C90.0413 (8)0.0722 (10)0.0605 (9)0.0220 (7)0.0050 (7)0.0028 (8)
C100.0371 (7)0.0616 (9)0.0467 (7)0.0073 (6)0.0082 (6)0.0028 (6)
C110.0330 (6)0.0436 (7)0.0350 (6)0.0037 (5)0.0009 (5)0.0029 (5)
C120.0760 (12)0.0747 (12)0.0563 (10)0.0039 (9)0.0107 (9)0.0193 (8)
C130.0508 (9)0.0459 (9)0.0940 (13)0.0107 (7)0.0068 (9)0.0146 (8)
C140.0490 (9)0.0716 (11)0.0649 (10)0.0161 (8)0.0047 (7)0.0021 (8)
C150.0334 (7)0.0613 (9)0.0393 (7)0.0025 (6)0.0036 (5)0.0043 (6)
C160.0420 (8)0.0808 (11)0.0434 (7)0.0005 (7)0.0018 (6)0.0056 (7)
N10.0350 (6)0.0442 (6)0.0537 (7)0.0002 (5)0.0026 (5)0.0073 (5)
N50.0294 (5)0.0513 (6)0.0369 (5)0.0030 (5)0.0025 (4)0.0014 (5)
O10.0380 (6)0.1162 (10)0.0492 (6)0.0051 (6)0.0072 (5)0.0230 (6)
Cl10.0581 (3)0.0963 (4)0.0461 (2)0.0130 (2)0.00504 (18)0.01223 (19)
Geometric parameters (Å, º) top
C2—N11.4825 (18)C10—C111.3979 (18)
C2—C31.527 (2)C10—H100.9300
C2—C131.528 (2)C11—N11.3793 (17)
C2—C121.532 (2)C12—H12A0.9600
C3—C41.5199 (19)C12—H12B0.9600
C3—H3A0.9700C12—H12C0.9600
C3—H3B0.9700C13—H13A0.9600
C4—N51.4734 (16)C13—H13B0.9600
C4—C141.512 (2)C13—H13C0.9600
C4—H40.9800C14—H14A0.9600
C6—C71.3896 (19)C14—H14B0.9600
C6—C111.3971 (18)C14—H14C0.9600
C6—N51.4327 (16)C15—O11.2184 (17)
C7—C81.376 (2)C15—N51.3453 (17)
C7—H70.9300C15—C161.523 (2)
C8—C91.374 (2)C16—Cl11.7656 (16)
C8—H80.9300C16—H16A0.9700
C9—C101.374 (2)C16—H16B0.9700
C9—H90.9300N1—H10.835 (19)
N1—C2—C3111.68 (11)C6—C11—C10117.15 (12)
N1—C2—C13108.47 (12)C2—C12—H12A109.5
C3—C2—C13111.52 (12)C2—C12—H12B109.5
N1—C2—C12107.62 (13)H12A—C12—H12B109.5
C3—C2—C12108.31 (12)C2—C12—H12C109.5
C13—C2—C12109.14 (14)H12A—C12—H12C109.5
C4—C3—C2117.06 (11)H12B—C12—H12C109.5
C4—C3—H3A108.0C2—C13—H13A109.5
C2—C3—H3A108.0C2—C13—H13B109.5
C4—C3—H3B108.0H13A—C13—H13B109.5
C2—C3—H3B108.0C2—C13—H13C109.5
H3A—C3—H3B107.3H13A—C13—H13C109.5
N5—C4—C14110.96 (12)H13B—C13—H13C109.5
N5—C4—C3109.75 (10)C4—C14—H14A109.5
C14—C4—C3112.07 (12)C4—C14—H14B109.5
N5—C4—H4108.0H14A—C14—H14B109.5
C14—C4—H4108.0C4—C14—H14C109.5
C3—C4—H4108.0H14A—C14—H14C109.5
C7—C6—C11120.75 (12)H14B—C14—H14C109.5
C7—C6—N5119.64 (12)O1—C15—N5122.55 (13)
C11—C6—N5119.56 (12)O1—C15—C16121.58 (13)
C8—C7—C6120.64 (14)N5—C15—C16115.87 (12)
C8—C7—H7119.7C15—C16—Cl1110.72 (11)
C6—C7—H7119.7C15—C16—H16A109.5
C9—C8—C7119.02 (14)Cl1—C16—H16A109.5
C9—C8—H8120.5C15—C16—H16B109.5
C7—C8—H8120.5Cl1—C16—H16B109.5
C8—C9—C10120.89 (14)H16A—C16—H16B108.1
C8—C9—H9119.6C11—N1—C2124.54 (12)
C10—C9—H9119.6C11—N1—H1112.6 (12)
C9—C10—C11121.33 (14)C2—N1—H1111.3 (12)
C9—C10—H10119.3C15—N5—C6121.36 (11)
C11—C10—H10119.3C15—N5—C4119.16 (11)
N1—C11—C6121.87 (12)C6—N5—C4119.29 (10)
N1—C11—C10120.84 (12)
N1—C2—C3—C470.58 (15)C6—C11—N1—C248.60 (19)
C13—C2—C3—C450.97 (17)C10—C11—N1—C2135.87 (15)
C12—C2—C3—C4171.08 (13)C3—C2—N1—C115.18 (19)
C2—C3—C4—N552.53 (16)C13—C2—N1—C11128.48 (15)
C2—C3—C4—C14176.30 (12)C12—C2—N1—C11113.57 (15)
C11—C6—C7—C84.6 (2)O1—C15—N5—C6169.69 (15)
N5—C6—C7—C8172.60 (14)C16—C15—N5—C610.9 (2)
C6—C7—C8—C90.5 (2)O1—C15—N5—C45.1 (2)
C7—C8—C9—C102.8 (3)C16—C15—N5—C4174.26 (13)
C8—C9—C10—C112.1 (3)C7—C6—N5—C1563.37 (18)
C7—C6—C11—N1179.24 (13)C11—C6—N5—C15113.83 (15)
N5—C6—C11—N13.60 (19)C7—C6—N5—C4111.44 (15)
C7—C6—C11—C105.1 (2)C11—C6—N5—C471.37 (16)
N5—C6—C11—C10172.09 (12)C14—C4—N5—C1586.63 (16)
C9—C10—C11—N1177.52 (15)C3—C4—N5—C15148.96 (12)
C9—C10—C11—C61.8 (2)C14—C4—N5—C688.29 (15)
O1—C15—C16—Cl121.9 (2)C3—C4—N5—C636.11 (17)
N5—C15—C16—Cl1157.53 (12)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O1i0.835 (19)2.276 (19)3.1049 (16)171.5 (17)
Symmetry code: (i) x+1/2, y+1/2, z+1/2.

Experimental details

Crystal data
Chemical formulaC14H19ClN2O
Mr266.76
Crystal system, space groupMonoclinic, P21/n
Temperature (K)293
a, b, c (Å)10.3971 (3), 12.2589 (3), 11.0994 (3)
β (°) 93.953 (1)
V3)1411.33 (7)
Z4
Radiation typeMo Kα
µ (mm1)0.26
Crystal size (mm)0.23 × 0.22 × 0.20
Data collection
DiffractometerBruker SMART APEXII CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2008)
Tmin, Tmax0.942, 0.949
No. of measured, independent and
observed [I > 2σ(I)] reflections
13339, 3568, 2767
Rint0.018
(sin θ/λ)max1)0.672
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.040, 0.120, 1.07
No. of reflections3568
No. of parameters167
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.22, 0.27

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O1i0.835 (19)2.276 (19)3.1049 (16)171.5 (17)
Symmetry code: (i) x+1/2, y+1/2, z+1/2.
 

Acknowledgements

SP thanks the UGC, New Delhi, for financial assistance in the form of a major research project.

References

First citationAllen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2 pp. 1–19.
First citationBruker (2008). APEX2, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
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