5-Chloro­acetyl-4-methyl-2,3,4,5-tetra­hydro-1H-1,5-benzodiazepin-2-one

K Ravichandran; P Sakthivel; S Ponnuswamy; P Ramesh; M N Ponnuswamy

doi:10.1107/S1600536809034813

. 2009 Sep 5;65(Pt 10):o2361. doi: 10.1107/S1600536809034813

5-Chloroacetyl-4-methyl-2,3,4,5-tetrahydro-1H-1,5-benzodiazepin-2-one

K Ravichandran ^a, P Sakthivel ^b, S Ponnuswamy ^b, P Ramesh ^a, M N Ponnuswamy ^a,^*

PMCID: PMC2970477 PMID: 21577829

Abstract

In the title compound, C₁₂H₁₃ClN₂O₂, the benzodiazepine ring adopts a distorted boat conformation. The carbonyl O atom and the Cl atom of the chloroacetyl group are in a cis conformation. The crystal packing is controlled by intermolecular C—H⋯O and N—H⋯O interactions.

Related literature

For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For puckering and asymmetry parameters, see: Cremer & Pople (1975 ▶); Nardelli (1983 ▶). For the use of benzodiazepines in the treatment of gastrointestinal and central nervous system disorders, see: Rahbaek et al. (1999 ▶).

Experimental

Crystal data

C₁₂H₁₃ClN₂O₂
M _r = 252.69
Monoclinic,
a = 16.7656 (4) Å
b = 8.8171 (2) Å
c = 17.0125 (4) Å
β = 105.803 (1)°
V = 2419.80 (10) Å³
Z = 8
Mo Kα radiation
μ = 0.31 mm⁻¹
T = 293 K
0.30 × 0.25 × 0.20 mm

Data collection

Bruker Kappa APEXII area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2001 ▶) T _min = 0.912, T _max = 0.940
17051 measured reflections
4087 independent reflections
2835 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.128
S = 1.02
4087 reflections
159 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; 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 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809034813/bt5035sup1.cif

e-65-o2361-sup1.cif^{(17.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809034813/bt5035Isup2.hkl

e-65-o2361-Isup2.hkl^{(196.3KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4⋯O2	0.98	2.32	2.6952 (17)	102
N1—H1⋯O1ⁱ	0.881 (18)	1.958 (18)	2.8375 (16)	176.4 (16)
C7—H7⋯O2ⁱⁱ	0.93	2.43	3.2818 (17)	153
C14—H14A⋯O1ⁱⁱⁱ	0.97	2.52	3.2411 (18)	131

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

KR thanks Dr Babu Varghese, SAIF, IIT-Madras, India, for his help with the data collection and the management of Kandaswami Kandar’s College, Velur, Namakkal, India, for their encouragement to pursue the programme.

supplementary crystallographic information

Comment

Benzodiazepines are known for their natural occurrence in filamentous fungi and actinomycetes of the genera pencillium, aspergillus and streptomyces. Benzodiazepines from aspergillus include asperlicin, which is used for treatment of gastrointestinal and central nervous system (CNS) disorders (Rahbaek et al.,1999). In view of these importance and to ascertain the molecular conformation, crystallographic study of the title compound has been carried out.

The ORTEP diagram of the title compound is shown in Fig.1. The benzodiazepine ring adopts a distorted boat conformation. The puckering parameters (Cremer & Pople, 1975) and the asymmetry parameters (Nardelli, 1983) for this ring are q₂ = 0.965 (1) Å, q₃ = 0.155 (1) Å, φ₂ = 144.0 (1)°, φ₃ = 11.4 (5)° and Δ2(C4)=7.8 (1)°. The sum of the bond angles at N1(359.4°) and N5(359.99°) of the benzodiazepine ring is in accrdance with sp² hybridization. The choloroacetyl group adopts an extended conformation, which is evidenced from the torsion angle N5—C13—C14—Cl1[-161.9 (1)°].

The crystal packing is controlled by C—H···O and N—H···O types of intra and intermolecular interactions in addition to van der Waals forces. Atom N1 at (x, y, z) donates a proton to O1 (-x + 1, -y, -z + 1), which forms a graph set motif of R²₂(8) dimer (Bernstein et al., 1995). The intermolecular hydrogen bond C14—H14A···O1 connect the dimers into a C9 one dimensional chain running along c–axis as shown in Fig 2. Thus the two dimensional network is connected by an intermolecular hydrogen bond C7—H7···O2 which leads to a C6 zig–zag chain running along b–axis.

Experimental

To a solution of tetrahydro-4-methyl-1,5-benzodiazepin-2-one (0.88 g, 5 mmol) in anhydrous benzene (50 ml) was added triethylamine (2.8 ml, 20 mmol) and chloroacetyl chloride (1.59 ml, 20 mmol). The contents were allowed to reflux on a water bath for 6hrs. The reaction mixture was washed with sodium bicarbonate solution (10%), water and dried. The crude mass was crystallized from ethanol.