(E)-2-(2,6-Dichloro­phen­yl)-2-(phenyl­imino)acetamide

Masaaki Tomura

doi:10.1107/S1600536807063891

. 2007 Dec 6;64(Pt 1):o170–o171. doi: 10.1107/S1600536807063891

(E)-2-(2,6-Dichlorophenyl)-2-(phenylimino)acetamide

Masaaki Tomura ^a,^*

PMCID: PMC2915237 PMID: 21200736

Abstract

In the title compound, C₁₄H₁₀Cl₂N₂O, which is an important synthetic precursor of a human immunodeficiency virus type 1 (HIV-1) inhibitor, the dihedral angle between the 2,6-dichlorophenyl ring and the phenyl ring is 69.4 (1)°. In the crystal structure, the molecules form centrosymmetric dimers via N—H⋯O hydrogen bonds with an R ₂ ²(8) motif. The dimers are connected by intermolecular C—H⋯O and C—H⋯π interactions.

Related literature

For the starting material, see: Reich et al. (1917 ▶). For human immunodeficiency virus type 1 inhibitors, see: Pauwels et al. (1993 ▶). For related literature on the crystal structures of α-anilinoacetamide derivatives, see: Peeters et al. (1993 ▶); Garg et al. (1993 ▶); Opatz & Ferenc (2005 ▶). For related literature on C—H⋯O hydrogen bonds, see: Taylor & Kennard (1982 ▶); Biradha et al. (1997 ▶); Batchelor et al. (2000 ▶). For related literature on C—H⋯π interactions, see: Malone et al. (1997 ▶); Tomura & Yamashita (2001 ▶); Nishio (2004 ▶). For related literature, see: Allen et al. (1987 ▶); Bernstein et al. (1995 ▶); Allen (2002 ▶).

Experimental

Crystal data

C₁₄H₁₀Cl₂N₂O
M _r = 293.14
Triclinic,
a = 7.8777 (2) Å
b = 9.1433 (3) Å
c = 10.0217 (4) Å
α = 102.170 (3)°
β = 91.795 (3)°
γ = 102.145 (2)°
V = 687.66 (4) Å³
Z = 2
Cu Kα radiation
μ = 4.19 mm⁻¹
T = 296 (1) K
0.50 × 0.40 × 0.05 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.229, T _max = 0.818
3020 measured reflections
2808 independent reflections
2499 reflections with I > 2σ(I)
R _int = 0.016
3 standard reflections frequency: 120 min intensity decay: 0.8%

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.135
S = 1.05
2808 reflections
173 parameters
H-atom parameters constrained
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1992 ▶); cell refinement: CAD-4 EXPRESS; data reduction: TEXSAN (Rigaku/MSC, 2000 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: PLATON (Spek, 2003 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536807063891/kp2151sup1.cif

e-64-0o170-sup1.cif^{(16.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807063891/kp2151Isup2.hkl

e-64-0o170-Isup2.hkl^{(137.9KB, 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
N2—H2A⋯O1ⁱ	0.86	2.08	2.935 (2)	172
N2—H2B⋯N1	0.86	2.37	2.708 (2)	104
C3—H3⋯O1ⁱⁱ	0.93	2.55	3.260 (2)	133
N2—H2B⋯Cg1ⁱⁱⁱ	0.86	2.76	3.484 (2)	143

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) . Cg1 is the centroid of the C8–C13 benzene ring.

Acknowledgments

The author thanks the Instrument Center of the Institute for Molecular Science for the X-ray structure analysis.

supplementary crystallographic information

Comment

The title compound, (I), is an important synthetic precursor of α-anilinophenylaceamide derivatives, which are potent human immunodeficiency virus type 1 (HIV-1) specific reverse transcriptase inhibitors (Pauwels et al., 1993). A search for α-anilinoaceamide structure in the Cambridge Structural Database (Version 5.28; Allen, 2002) revealed three examples (Peeters et al., 1993; Garg et al., 1993; Opatz & Ferenc, 2005) while no structure of an α-phenyliminoaceamide derivative, such as (I), was found. We report here the molecular and crystal structures of the title α-phenyliminoaceamide derivative (I) (Fig. 1).

The compound (I) was synthesized by the reaction of N-(2,6-dichlorobenzylidene)aniline (Reich et al., 1917) with NaCN and crystallizes in the P1 space group with one molecule in an asymmetric unit. The molecule has an E-conformation about the C7?N1 bond. The bond lengths and angles are within the normal ranges (Allen et al., 1987). Two benzene rings of (I) are planar [r.m.s. deviations of 0.0047 (C1—C6) and 0.0074 (C8—C13) Å from the least-squares planes] with a dihedral angle between their least-squares planes of 69.4 (1)°. Each benzene ring is close to be orthogonal [86.5 (2) for C1—C6 and 73.9 (1)° for C8—C13] to the plane of the amide group (C14/O1/N2). In the amide group, the intramolecular hydrogen bond between atoms N1 and N2 is observed [2.708 (2) Å].

In the crystal structure, the molecules are linked via N—H···O hydrogen bonds [2.935 (2) Å for N2—H2A···O1(-x + 1, -y + 1, -z + 1)] to form a centrosymmetric dimer with a graph-set motif (Bernstein et al., 1995) of R₂²(8) (Fig. 2 and Table 1). The intermolecular C—H···O [3.260 (2) Å for C3—H3···O1(-x + 1, -y + 1, -z + 2)] and C—H···π [3.484 (2) Å for N2—H2B···Cg1(-x, -y, -z + 1), Cg1 is the centroid of the benzene ring (C8—C13)] interactions are observed between the dimers (Tomura & Yamashita, 2001; Nishio, 2004). The C—H···O hydrogen bond in the crystal structure of (I) is stronger than the typical C—H···O hydrogen bonds in other structures (Taylor & Kennard, 1982; Biradha et al., 1997; Batchelor et al., 2000). The C—H···π interaction corresponds to a geometry of type III (Malone et al., 1997).

Experimental

The compound (I) was prepared as follows: a mixture of N-(2,6-dichlorobenzylidene)aniline (Reich et al., 1917) (504 mg, 2.0 mmol) and NaCN (110 mg, 2.0 mmol) in dimethyl sulfoxide (20 ml) was stirred for 1 day at 296 K. The reaction mixture was poured into water (100 ml) and the solution was extracted with dichloromethane (100 ml × 3). The organic layer was washed with water and dried over Na₂SO₄. After the solvent was evaporated in vacuo, dichloromethane (10 ml) was added to the residue. The resulting colourless precipitate was collected to give 198 mg (34% yield) of (I). Physical data for (I): m.p. 510 K; ¹H NMR (CDCl₃, δ p.p.m.): 5.30–5.65 (br s, 1H), 6.81–7.26 (m, 8H), 7.37–7.47 (br s, 1H); MS (EI): m/z 294 (M⁺+2), 292 (M⁺), 248. Colourless crystals of (I) suitable for X-ray analysis were grown from a chloroform solution.