1-{1-[2,8-Bis(trifluoro­meth­yl)-4-quin­olyl]-5-methyl-1H-1,2,3-triazol-4-yl}ethanone

H C Devarajegowda; S Jeyaseelan; V Sumangala; Bojapoojary; Suresh P Nayak

doi:10.1107/S1600536810034926

. 2010 Sep 8;66(Pt 10):o2512–o2513. doi: 10.1107/S1600536810034926

1-{1-[2,8-Bis(trifluoromethyl)-4-quinolyl]-5-methyl-1H-1,2,3-triazol-4-yl}ethanone

H C Devarajegowda ^a,^*, S Jeyaseelan ^a, V Sumangala ^b, Bojapoojary ^c, Suresh P Nayak ^c

PMCID: PMC2983247 PMID: 21587507

Abstract

There are two independent molecules in the asymmetric unit of the title compound, C₁₆H₁₀F₆N₄O. The triazole ring is not coplanar with the quinoline ring system; the dihedral angle between the two planes being 74.47 (12) and 63.97 (13)° in the two molecules. The crystal structure is characterized by intermolecular C—H⋯F, C—H⋯N and C—H⋯O hydrogen bonding. Weak intramolecular C—H⋯F interactions are observed. Disorder is observed in two F atoms of one of the trifluoromethyl groups of one independent molecule [occupancy ratios 0.77 (3):0.23 (3) and 0.77 (4):0.23 (4)] and in all three F atoms of one of the trifluoromethyl groups of the second independent molecule [occupancy ratios 0.520 (14):0.480 (14), 0.615 (17):0.385 (17) and 0.783 (11):0.217 (11)]. The O atom is also disordered over two positions with occupancies of 0.60 (13) and 0.40 (13) in the first molecule.

Related literature

For general background to triazoles and their benzo derivatives, see: Sanghvi et al. (1990 ▶); Bohm & Karow (1981 ▶); Holla et al. (2005 ▶); Biagi et al. (2004 ▶); Karimkulov et al. (1991 ▶); Sherement et al. (2004 ▶); Savini et al. (1994 ▶); Banu et al. (1999 ▶); Julino & Stevens (1998 ▶); Diana & Nitz (1993 ▶); Manfredini et al. (2000 ▶); Rene et al. (1986 ▶); Passannanti et al. (1998 ▶); Deng et al. (2008 ▶); Sector & Bardeleben (1971 ▶); Barnard et al. (1993 ▶). For a related structure, see: Al-eryani et al. (2010 ▶).

Experimental

Crystal data

C₁₆H₁₀F₆N₄O
M _r = 388.28
Monoclinic,
a = 14.064 (2) Å
b = 8.7275 (13) Å
c = 27.468 (4) Å
β = 94.172 (2)°
V = 3362.6 (9) Å³
Z = 8
Mo Kα radiation
μ = 0.15 mm⁻¹
T = 293 K
0.20 × 0.20 × 0.15 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: ψ scan (SADABS; Bruker, 2001 ▶) T _min = 0.972, T _max = 0.979
23473 measured reflections
5923 independent reflections
4754 reflections with I > 2σ(I)
R _int = 0.028

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.139
S = 1.05
5923 reflections
547 parameters
63 restraints
H-atom parameters constrained
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); 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 I, global. DOI: 10.1107/S1600536810034926/ds2049sup1.cif

e-66-o2512-sup1.cif^{(31.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810034926/ds2049Isup2.hkl

e-66-o2512-Isup2.hkl^{(284.1KB, 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
C5—H5⋯F12	0.93	2.51	3.178 (3)	129
C9—H9⋯N7ⁱ	0.93	2.47	3.312 (4)	151
C16—H16A⋯O2ⁱⁱ	0.96	2.49	3.359 (4)	150
C32—H32B⋯F5Aⁱⁱⁱ	0.96	2.41	3.324 (14)	158

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

Acknowledgments

The authors thank Professor T. N. Guru Row and Mr Ravish Sankolli, Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, for their help with the data collection.

supplementary crystallographic information

Comment

1,2,3-Triazoles and their benzoderivatives have attracted considerable attention because of their theoretical interest and synthetic value. They also find numerous applications in industry and agriculture due to their extensive biological activitiesand successful application as fluorescent whiteners, light stabilizers and optical brightening agents (Sanghvi et al., 1990).Functionalized 1, 2,3-triazoles constitute one of the common fragments present in biologically active compounds (Bohm et al.,1981).This has resulted in a wealth of synthetic methodology for their preparation and incorporation in more complex structures.The accentuated interest in these compounds continues to be expressed in the pharmaceutical community and biological properties of these agents have been the subject of ongoing investigations (Holla et al., 2005). The triazole scaffold has a wide range of therapeutic uses as it is ubiquitously found in drugs. The derivatives of 1, 2, 3-triazoles constitute an important family of heterocyclic compounds due to their chemotherapeutical values (Sanghvi et al., 1990). Some 1,2,3-triazoles are used as DNA cleaving agents and potassium channels activators (Biagi et al., 2004). Since many of them have remarkable antimicrobial(Karimkulov et al., 1991; Sherement et al., 2004), analgesic & anti-inflammatory (Savini et al. ,1994), local anesthetic (Banu et al. , 1999), antimalarial (Julino et al. , 1998), antiviral (Diana et al. ,1993), anti-proliferatine (Manfredini et al. ,2000), anticonvulsant (Rene et al. ,1986), antineoplastic(Passannanti et al. , 1998) and anticancer activity (Deng et al. ,2008), their synthesis and transformations have been received particular interest for a long time.

Fluorine incorporated compounds exhibit dramatically improved potency compared to their non-fluorinated analogues (Sector et al. ,1971) since its incorporation alters the electronic, lipophilic and steric parameters and can critically increase the intrinsic activity,chemical and metabolic stability.In particular, introduction of CF₃ group in organic molecules immensely increased the pharmacological activity as well as lipophilicity (Barnard et al. ,1993).

The structure of 1-{1-[2,8-bis(trifluoromethyl) quinolin-4-yl]-5- methyl-1H-1,2,3-triazol-4-yl}ethanone contains two independent molecules in the asymmetric unit. The triazole ring is not coplanar with the quinoline ring system; the dihedral angle between the two planes is 74.21 (08)°. The structure of the molecules is stabilized by intermolecular C5–H5···F12 & C9–H9···N7, C16–H16A···O2 & C32–H32B···F5A and weak intramolecular C3–H3···F3 & C25–H25···F12 hydrogen bonding (Table 1) and shows two fluorine atoms disordered in one of the trifluoromethyl group and oxygen atom.

Experimental

A solution of 4-Azido-2,8 bis trifluoro methyl quinoline (2.5 g,0.08 mol) in 25 mL me thanol was treated with acetyl acetone (0.9 g, 0.008 mol) and the mixture was cooled to 0°C. Sodium methoxide (0.008 mol) was added in lots under nitrogen over a period of 30 minutes. It was then stirred for 30 minutes. The progress of the reaction was monitored by TLC using ethyl acetate: hexane (1: 4, v/v) as mobile phase. The reaction mass is quenched to ice water. The title compound is isolated by filtration as a yellow solid. The recrystallization of the compound in methanol gave 76% of pure compound. Melting point: 427 K. Mol.Wt: 388.27 IR (KBr, γ/cm^-1): 3025 (Ar—H), 1715 (C=O), 1005(C—F). ¹H NMR (300 MHz, CDCl₃): δ, 2.52(s, CH₃, 3H), 2.83(s, 3H, COCH₃), 7.26(s, Ar—H,1H), 7.65–7.68(d, 1H, Ar—H, J =8.4 Hz),8.32–8.34 (d, 1H, Ar—H, J =7.2 Hz), 7.83–7. 86 (t, IH, Ar—H, J =7.8 Hz). MS (m/z, %):388 (M⁺). Anal. calcd for C₁₆ H₁₀F₆N₄O (in %): C-49.47, H-2.61, N-14.44. Found C-49.49, H-2.60, N-14.43.