N,N′-[4,4′-Methyl­enebis(4,1-phenyl­ene)]bis­(2,6-difluoro­benzamide)

Mohammad T M Al-Dajani; Jamal Talaat; Nornisah Mohamed; Madhukar Hemamalini; Hoong-Kun Fun

doi:10.1107/S1600536811024524

. 2011 Jun 30;67(Pt 7):o1832. doi: 10.1107/S1600536811024524

N,N′-[4,4′-Methylenebis(4,1-phenylene)]bis(2,6-difluorobenzamide)

Mohammad T M Al-Dajani ^a, Jamal Talaat ^b, Nornisah Mohamed ^a, Madhukar Hemamalini ^c, Hoong-Kun Fun ^c,^*,^‡

PMCID: PMC3151792 PMID: 21837199

Abstract

The complete molecule of the title compound, C₂₇H₁₈F₄N₂O₂, is generated by crystallographic twofold symmetry, with one C atom lying on the rotation axis. The dihedral angle between fluoro-substituted phenyl ring and the adjacent benzene ring is 10.37 (5)°. In the crystal, molecules are connected by N—H⋯O and C—H⋯F hydrogen bonds, resulting in supramolecular chains propagating along the c direction.

Related literature

For applications of benzamide derivatives, see: Ashwood et al. (1990 ▶); Kees et al. (1989 ▶); Ragavan et al. (2010 ▶); Carmellino et al. (1994 ▶); Rauko et al. (2001 ▶). For a related structure, see: Cronin et al. (2000 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₂₇H₁₈F₄N₂O₂
M _r = 478.43
Monoclinic,
a = 42.0478 (10) Å
b = 5.2980 (1) Å
c = 9.5643 (2) Å
β = 92.522 (2)°
V = 2128.57 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 100 K
0.48 × 0.38 × 0.05 mm

Data collection

Bruker APEXII DUO CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.946, T _max = 0.994
26445 measured reflections
3871 independent reflections
3172 reflections with I > 2σ(I)
R _int = 0.031

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.114
S = 1.06
3871 reflections
163 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.43 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811024524/hb5924sup1.cif

e-67-o1832-sup1.cif^{(17.3KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811024524/hb5924Isup2.hkl

e-67-o1832-Isup2.hkl^{(186KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811024524/hb5924Isup3.cml

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
N1—H1N1⋯O1ⁱ	0.841 (15)	2.078 (15)	2.8811 (11)	159.4 (14)
C9—H9A⋯F1ⁱⁱ	0.95	2.41	3.2318 (11)	145

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

Acknowledgments

NM gratefully acknowledges funding from Universiti Sains Malaysia under the University Research Grant (No. 1001/PFARMASI/821142). HKF and MH thank the Malaysian Government and Universiti Sains Malaysia for the Research University Grant No. 1001/PFIZIK/811160. MH also thanks Universiti Sains Malaysia for a post-doctoral research fellowship.

supplementary crystallographic information

Comment

A number of benzamide derivatives were reported to possess anti-hypertensive (Ashwood et al., 1990), anti-diabetic (Kees et al., 1989), anti-bacterial (Ragavan et al., 2010), anti-fungal (Carmellino et al., 1994) and anti-cancer (Rauko et al., 2001) activities. As a part of our study on the synthesis of new fluorine- containing compounds with possible biological activities, we report here the crystal structure of the title compound, (I).

The asymmetric unit of the title compound, (Fig. 1), consists of a half molecule of N,N'-(4,4'-methylenebis(4,1-phenylene))bis (2,6-difluorobenzamide), which has a twofold symmetry and it adopts an E, E conformation. The dihedral angle between fluoro- substituted phenyl (C1–C6) rings and benzene (C8–13) ring is 10.37 (5)°. All bond lengths and angles are comparable to values observed in a closely related benzamide structure (Cronin et al., 2000).

In the crystal structure (Fig. 2), the adjacent molecules are connected via N1—H1N1..O1 and C9—H9A···F1 (Table 1) hydrogen bonds forming one-dimensional supramolecular chains along the c-axis.

Experimental

In a round bottom flask, 25ml of tetrahydrofuran (THF) was mixed with 4,4'-diaminodiphenylmethane (0.01 mol,2 g) with stirring. Drops of 2,6-Difluorobenzylchloride (0.02 mol, 3.4 g ) which was dissolved in THF was then added. The mixture was refluxed for 30 min and the yellow precipitate formed was filtered and washed with alkaline water, then with toluene and further washed with dilute hydrochloric acid. The precipate was dissolved in methanol at room temperature yielding colourless plates of (I).