2,6-Di­fluoro-N-(prop-2-yn­yl)benzamide

Zahid Hussain; Ejaz Hussain; Hina Siddiqui; M Iqbal Choudhary; Sammer Yousuf

doi:10.1107/S1600536813021120

. 2013 Aug 17;69(Pt 9):o1440. doi: 10.1107/S1600536813021120

2,6-Difluoro-N-(prop-2-ynyl)benzamide

Zahid Hussain ^a, Ejaz Hussain ^a, Hina Siddiqui ^a, M Iqbal Choudhary ^a,^b, Sammer Yousuf ^a,^*

PMCID: PMC3884469 PMID: 24427068

Abstract

In the molecule of the title difluorobenzamide derivative, C₁₀H₇F₂NO, the angle formed by the least-squares mean line through the prop-2-ynyl group [maximum deviation = 0.011 (3) Å] and the normal to the benzene ring is 59.03 (7)°. In the crystal, molecules are linked via N—H⋯O and C—H⋯F hydrogen bonds into layers parallel to the ac plane.

Related literature

For the biological activity of difluorobenzamide derivatives, see: Chang et al. (2002 ▶); Kees et al. (1989 ▶); Ragavan et al. (2010 ▶); Carmellino et al. (1994 ▶); Rauko et al. (2001 ▶). For the crystal structure of a related compound, see: Fun et al. (2010 ▶).

Experimental

Crystal data

C₁₀H₇F₂NO
M _r = 195.17
Monoclinic,
a = 5.0479 (8) Å
b = 19.738 (3) Å
c = 9.2428 (15) Å
β = 91.432 (4)°
V = 920.6 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 273 K
0.38 × 0.17 × 0.10 mm

Data collection

Bruker SMART APEX CCD diffractometer
5388 measured reflections
1669 independent reflections
1283 reflections with I > 2σ(I)
R _int = 0.022

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.099
S = 1.03
1669 reflections
135 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.13 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813021120/rz5082sup1.cif

e-69-o1440-sup1.cif^{(19.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813021120/rz5082Isup2.hkl

e-69-o1440-Isup2.hkl^{(82.2KB, hkl)}

Click here for additional data file.^{(3.4KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813021120/rz5082Isup3.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—H1⋯O1ⁱ	0.83 (2)	2.10 (2)	2.8387 (19)	147.4 (17)
C2—H2A⋯F2ⁱⁱ	0.93	2.49	3.394 (2)	164

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

supplementary crystallographic information

1. Comment

Some difluorobenzamide derivatives are known to have excellent antiviral and antiproliferation activities (Chang et al., 2002). They are also well known for their anti-diabetic (Kees et al., 1989), anti-fungal (Carmellino et al., 1994), anti-bacterial (Ragavan et al., 2010) and anti-cancer (Rauko et al., 2001) properties.

The structure of the title fluorinated benzamide derivative (Fig. 1) is distinctly similar to that of the previously reported compound N-(4-cyanophenyl)-2,6-difluorobenzamide (Fun et al., 2010), with the difference that the N-(4-cyanophenyl) moiety is replaced by a prop-2-ynyl chain (C8–C10). The observed distance for the C9—C10 acetylene bond is 1.162 (3) Å. The angle between the least-squares mean line through the prop-2-ynyl group (maximum deviation 0.011 (3) Å for atom C9) and the normal to the benzene ring is 59.03 (7)°. The molecule has no prominent intramolecular non-covalent interactions. In the crystal, molecules are linked via C—H···F (Fig. 2) and N—H···O hydrogen bonds (Table 1) to form layers parallel to the ac plane. No π···π stacking interactions are observed.

2. Experimental

Prop-2-yn-1-amine (36.3 mmol, 1.0 eq) was dissolved in dichloromethane (20 mL) in a round bottom flask and kept at 0 °C. Diisopropylethylamine (DIPEA) (145 mmol, 4.0 eq) and 2,6-diflurobenzoyl chloride (54.4 mmol, 1.5 eq) were then added and the mixture stirred for 1.5 h. Progress of the reaction was monitored by thin layer chromatography. On completion of the reaction the mixture was dissolved in water and extracted with diethyl ether (2 × 25 mL). The organic layer was dried with anhydrous Na₂SO₄ and concentrated to obtain a crude gummy product. The crude product was finally purified by flash column chromatography by using EtOAc/hexane (3:7 v/v) as eluent to afford the title compound in 77% yield. Crystals suitable for X-ray analysis were obtained by slow evaporation of an ethanol solution.