organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 69| Part 12| December 2013| Pages o1853-o1854

3,4-Di­methyl­phenyl quinoline-2-carboxyl­ate

aDepartment of Chemistry, Yuvaraja's College, Mysore 570 005, India, bDepartment of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India, cP.P.S.F.T. Department, Central Food Technplogy Research institute, Mysore 570 005, India, and dDepartment of Chemistry, Keene State College, 229 Main Street, Keene, NH 03435-2001, USA
*Correspondence e-mail: jjasinski@keene.edu

(Received 24 November 2013; accepted 25 November 2013; online 30 November 2013)

In the title compound, C18H15NO2, the dihedral angle between the mean planes of the quinoline ring system and the phenyl ring is 48.1 (5)°. The mean plane of the carboxyl­ate group is twisted from the mean planes of the latter by 19.8 (8) and 64.9 (5)°, respectively. The crystal packing features weak C—H⋯O inter­actions, which form chains along [010].

Related literature

For heterocycles in natural products, see: Morimoto et al. (1991[Morimoto, Y., Matsuda, F. & Shirahama, H. (1991). Synlett, 3, 202-203.]); Michael (1997[Michael, J. P. (1997). Nat. Prod. Rep. 14, 605-608.]). For heterocycles in fragrances and dyes, see: Padwa et al. (1999[Padwa, A., Brodney, M. A., Liu, B., Satake, K. & Wu, T. (1999). J. Org. Chem. 64, 3595-3607.]). For heterocycles in biologically active compounds, see: Markees et al. (1970[Markees, D. G., Dewey, V. C. & Kidder, G. W. (1970). J. Med. Chem. 13, 324-326.]); Campbell et al. (1988[Campbell, S. F., Hardstone, J. D. & Palmer, M. J. (1988). J. Med. Chem. 31,1031-1035.]). For the use of quinoline alkaloids as drugs for the treatment of malaria, see: Robert & Meunier (1998[Robert, A. & Meunier, B. (1998). Chem. Soc. Rev. 27, 273-279.]). For quinoline as a privileged scaffold in cancer drug discovery, see: Solomon & Lee (2011[Solomon, V. R. & Lee, H. (2011). Curr. Med. Chem. 18, 1488-1508.]). For related structures, see: Fazal et al. (2012[Fazal, E., Jasinski, J. P., Krauss, S. T., Sudha, B. S. & Yathirajan, H. S. (2012). Acta Cryst. E68, o3231-o3232.]); Butcher et al. (2007[Butcher, R. J., Jasinski, J. P., Mayekar, A. N., Yathirajan, H. S. & Narayana, B. (2007). Acta Cryst. E63, o3603.]); Jing & Qin (2008[Jing, L.-H. & Qin, D.-B. (2008). Z. Kristallogr. 223, 35-36.]); Jasinski et al. (2010[Jasinski, J. P., Butcher, R. J., Mayekar, A. N., Yathirajan, H. S., Narayana, B. & Sarojini, B. K. (2010). J. Mol. Struct. 980, 172-181.]). For standard bond lengths, see: Allen et al. (1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]).

[Scheme 1]

Experimental

Crystal data
  • C18H15NO2

  • Mr = 277.32

  • Monoclinic, P 21 /c

  • a = 6.19172 (17) Å

  • b = 15.4196 (4) Å

  • c = 14.6585 (4) Å

  • β = 90.761 (3)°

  • V = 1399.38 (7) Å3

  • Z = 4

  • Cu Kα radiation

  • μ = 0.69 mm−1

  • T = 173 K

  • 0.44 × 0.22 × 0.16 mm

Data collection
  • Agilent Xcalibur (Eos, Gemini) diffractometer

  • Absorption correction: multi-scan (CrysAlis PRO and CrysAlis RED; Agilent, 2012[Agilent (2012). CrysAlis PRO and CrysAlis RED. Agilent Technologies, Yarnton, England.]) Tmin = 0.921, Tmax = 1.000

  • 8355 measured reflections

  • 2740 independent reflections

  • 2387 reflections with I > 2σ(I)

  • Rint = 0.042

Refinement
  • R[F2 > 2σ(F2)] = 0.042

  • wR(F2) = 0.121

  • S = 1.05

  • 2740 reflections

  • 193 parameters

  • H-atom parameters constrained

  • Δρmax = 0.28 e Å−3

  • Δρmin = −0.24 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C8—H8⋯O1i 0.93 2.48 3.2735 (16) 144
Symmetry code: (i) [-x, y-{\script{1\over 2}}, -z+{\script{1\over 2}}].

Data collection: CrysAlis PRO (Agilent, 2012[Agilent (2012). CrysAlis PRO and CrysAlis RED. Agilent Technologies, Yarnton, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis RED (Agilent, 2012[Agilent (2012). CrysAlis PRO and CrysAlis RED. Agilent Technologies, Yarnton, England.]); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007[Palatinus, L. & Chapuis, G. (2007). J. Appl. Cryst. 40, 786-790.]); program(s) used to refine structure: SHELXL2012 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: OLEX2 (Dolomanov et al., 2009[Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339-341.]); software used to prepare material for publication: OLEX2.

Supporting information


Comment top

Quinoline-2 carboxylic acid derivatives are a class of important materials as anti-tuberculosis agents, as fluorescent reagents, hydrophobic field-detection reagents, visualisation reagents, fluorescent labelled peptide probes and as antihyperglycemics. Quinoline derivatives represent a major class of heterocycles and are found in natural products(Morimoto et al., 1991; Michael, 1997), numerous commercial products, including fragrances, dyes(Padwa et al., 1999)and biologically active compounds (Markees et al., 1970; Campbell et al., 1988). Quinoline alkaloids such as quinine,chloroquin, mefloquine and amodiaquine are used as efficient drugs for the treatment of malaria (Robert & Meunier,1998). Quinoline has been used as a privileged scaffold in cancer drug discovery (Solomon & Lee, 2011). The crystal structures of 4-methylphenyl quinoline-2-carboxylate (Fazal et al.,2012), 1-(quinolin-2-yl)ethanone(Butcher et al., 2007) and methyl quinoline-2-carboxylate (Jing & Qin, 2008) and the synthesis, crystal structures and theoretical studies of four Schiff bases derived from 4-hydrazinyl-8-(trifluoromethyl) quinoline (Jasinski et al., 2010) have been reported. In view of the importance of quinolines, this paper reports the crystal structure of the title compound, (I), C18H15NO2.

In the title compound, C18H15NO2, the dihedral angle between the mean planes of the quinoline ring and the phenyl ring is 48.1 (5)° (Fig. 1). The mean plane of the carboxylate group is twisted from the mean planes of the quinoline ring and phenyl ring by 19.8 (8)° and 64.9 (5)°, respectively. The crystal packing is influenced by weak C8—H8···O1 intermolecular interactions making chains along [0 1 0](Fig. 2). No classical hydrogen bonds were observed.

Related literature top

For heterocycles in natural products, see: Morimoto et al. (1991); Michael (1997). For heterocycles in fragrances and dyes, see: Padwa et al. (1999). For heterocycles in biologically active compounds, see: Markees et al. (1970); Campbell et al. (1988). For the use of quinoline alkaloids as efficient drugs for the treatment of malaria, see: Robert & Meunier (1998). For quinoline as a privileged scaffold in cancer drug discovery, see: Solomon & Lee (2011). For related structures, see: Fazal et al. (2012); Butcher et al. (2007); Jing & Qin (2008); Jasinski et al. (2010). For standard bond lengths, see: Allen et al. (1987).

Experimental top

The title compound was prepared by the following procedure: To a mixture of 1.73 g (10 mmole) of quinaldic acid and 1.56 g (10 mmole) of 3,4-dimethylphenol in a round-bottomed flask fitted with a reflex condenser with a drying tube is added 0.15 g (10 mmole) of phosphorous oxychloride. The mixture is heated with occasional swirling, and temperature is maintained at 348-353 K. At the end of eight hours the reaction mixture is poured in to a solution of 2 g of sodium bicarbonate in 25 mL of water. The precipitated ester is collected on a filter and washed with water. The yield of crude, air dried 3,4-dimethyl phenyl quinoline-2-carboxylate is 1.47 to 1.90 g (50-65%). X-ray quality crystal was obtained by recrystallization from absolute ethanol.(M.P.:397 K)

Refinement top

All of the H atoms were placed in their calculated positions and then refined using the riding model with Atom—H lengths of 0.93Å (CH) or 0.96Å (CH3). Isotropic displacement parameters for these atoms were set to 1.2 (CH) or 1.5 (CH3) times Ueq of the parent atom. Idealised Me refined as rotating group.

Computing details top

Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis RED (Agilent, 2012); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: SHELXL2012 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

Figures top
[Figure 1] Fig. 1. ORTEP drawing of (I) (C18H15NO2) showing the labeling scheme with 50% probability displacement ellipsoids.
[Figure 2] Fig. 2. Molecular packing for (I) viewed along the a axis. Dashed lines indicate weak C8—H8···O1 intermolecular interactions making chains along [0 1 0] and influence the crystal packing. The remaining H atoms have been removed for clarity.
3,4-Dimethylphenyl quinoline-2-carboxylate top
Crystal data top
C18H15NO2F(000) = 608
Mr = 277.32Dx = 1.316 Mg m3
Monoclinic, P21/cCu Kα radiation, λ = 1.54184 Å
a = 6.19172 (17) ÅCell parameters from 6294 reflections
b = 15.4196 (4) Åθ = 4.7–72.3°
c = 14.6585 (4) ŵ = 0.69 mm1
β = 90.761 (3)°T = 173 K
V = 1399.38 (7) Å3Irregular, clear red
Z = 40.44 × 0.22 × 0.16 mm
Data collection top
Agilent Xcalibur (Eos, Gemini)
diffractometer
2740 independent reflections
Radiation source: Enhance (Cu) X-ray Source2387 reflections with I > 2σ(I)
Detector resolution: 16.0416 pixels mm-1Rint = 0.042
ω scansθmax = 72.3°, θmin = 4.2°
Absorption correction: multi-scan
(CrysAlis PRO and CrysAlis RED; Agilent, 2012)
h = 76
Tmin = 0.921, Tmax = 1.000k = 1819
8355 measured reflectionsl = 1418
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.042 w = 1/[σ2(Fo2) + (0.0716P)2 + 0.1805P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.121(Δ/σ)max < 0.001
S = 1.05Δρmax = 0.28 e Å3
2740 reflectionsΔρmin = 0.24 e Å3
193 parametersExtinction correction: SHELXL2012 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.0048 (6)
Primary atom site location: structure-invariant direct methods
Crystal data top
C18H15NO2V = 1399.38 (7) Å3
Mr = 277.32Z = 4
Monoclinic, P21/cCu Kα radiation
a = 6.19172 (17) ŵ = 0.69 mm1
b = 15.4196 (4) ÅT = 173 K
c = 14.6585 (4) Å0.44 × 0.22 × 0.16 mm
β = 90.761 (3)°
Data collection top
Agilent Xcalibur (Eos, Gemini)
diffractometer
2740 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO and CrysAlis RED; Agilent, 2012)
2387 reflections with I > 2σ(I)
Tmin = 0.921, Tmax = 1.000Rint = 0.042
8355 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0420 restraints
wR(F2) = 0.121H-atom parameters constrained
S = 1.05Δρmax = 0.28 e Å3
2740 reflectionsΔρmin = 0.24 e Å3
193 parameters
Special details top

Experimental. 1H NMR(500 MHz,DMSO) δ 8.66 (1H,d, J= 8.5Hz), 8.26(1H,d, J= 8.5Hz),8.24(1H,d, J= 8.5 Hz), 8.15(1H,d, J= 8.03 Hz),7.93(1H,dt, J1= 8.2Hz, J2=6.46, J3=1.08Hz), 7.8(1H,t, J= 7.5Hz), 7.25(1H,d, J= 8.2Hz), 7.14(1H,d, J= 2.15Hz), 7.06(1H,dd, J1= 8.03Hz,J2=2.35),2.28(3H,s),2.25(3H,s).

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.03672 (17)0.48206 (6)0.20779 (8)0.0457 (3)
O20.26816 (14)0.53658 (5)0.10569 (6)0.0302 (2)
N10.23607 (16)0.32280 (7)0.18546 (7)0.0247 (2)
C10.19203 (19)0.47407 (8)0.16176 (8)0.0269 (3)
C20.33036 (19)0.39405 (8)0.15562 (8)0.0247 (3)
C30.54041 (19)0.39753 (8)0.11950 (8)0.0286 (3)
H30.59960.45000.10100.034*
C40.65466 (19)0.32226 (8)0.11227 (8)0.0287 (3)
H40.79450.32290.08990.034*
C50.55877 (19)0.24325 (8)0.13906 (8)0.0258 (3)
C60.6605 (2)0.16151 (9)0.12935 (9)0.0315 (3)
H60.79760.15830.10440.038*
C70.5586 (2)0.08740 (9)0.15634 (9)0.0358 (3)
H70.62580.03400.14870.043*
C80.3518 (2)0.09127 (8)0.19569 (9)0.0339 (3)
H80.28520.04040.21460.041*
C90.2485 (2)0.16894 (8)0.20625 (9)0.0284 (3)
H90.11290.17070.23280.034*
C100.34768 (19)0.24685 (8)0.17682 (8)0.0240 (3)
C120.26169 (19)0.69008 (8)0.12548 (8)0.0254 (3)
H120.39950.68630.15120.031*
C130.1647 (2)0.77085 (8)0.11323 (8)0.0263 (3)
C140.0431 (2)0.77561 (8)0.07407 (8)0.0280 (3)
C150.1486 (2)0.69903 (9)0.04954 (8)0.0296 (3)
H150.28700.70200.02430.036*
C160.0521 (2)0.61829 (8)0.06192 (8)0.0287 (3)
H160.12400.56760.04530.034*
C170.1535 (2)0.61561 (8)0.09951 (8)0.0257 (3)
C180.2807 (2)0.85201 (9)0.14296 (10)0.0362 (3)
H18A0.41970.83700.16810.054*
H18B0.19740.88130.18840.054*
H18C0.29890.88950.09130.054*
C190.1517 (2)0.86210 (9)0.05940 (10)0.0402 (3)
H19A0.17320.88970.11730.060*
H19B0.28880.85350.02940.060*
H19C0.06220.89810.02220.060*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0474 (6)0.0355 (5)0.0550 (7)0.0099 (4)0.0268 (5)0.0120 (4)
O20.0339 (5)0.0233 (5)0.0335 (5)0.0028 (3)0.0083 (4)0.0041 (3)
N10.0242 (5)0.0260 (5)0.0240 (5)0.0007 (4)0.0019 (4)0.0017 (4)
C10.0291 (6)0.0257 (6)0.0258 (6)0.0021 (5)0.0025 (5)0.0001 (5)
C20.0269 (6)0.0256 (6)0.0215 (6)0.0014 (4)0.0000 (4)0.0012 (4)
C30.0282 (6)0.0287 (6)0.0290 (6)0.0052 (5)0.0021 (5)0.0046 (5)
C40.0223 (6)0.0356 (7)0.0282 (6)0.0012 (5)0.0040 (5)0.0033 (5)
C50.0259 (6)0.0295 (6)0.0221 (6)0.0010 (5)0.0008 (4)0.0010 (4)
C60.0290 (6)0.0362 (7)0.0293 (6)0.0059 (5)0.0024 (5)0.0002 (5)
C70.0438 (8)0.0273 (7)0.0362 (7)0.0085 (5)0.0010 (6)0.0010 (5)
C80.0420 (7)0.0246 (6)0.0352 (7)0.0038 (5)0.0012 (6)0.0027 (5)
C90.0276 (6)0.0290 (6)0.0288 (6)0.0035 (5)0.0019 (5)0.0021 (5)
C100.0250 (6)0.0256 (6)0.0214 (6)0.0004 (4)0.0007 (4)0.0010 (4)
C120.0253 (6)0.0283 (6)0.0228 (6)0.0005 (5)0.0009 (5)0.0003 (4)
C130.0314 (6)0.0255 (6)0.0221 (6)0.0004 (5)0.0041 (5)0.0012 (4)
C140.0306 (6)0.0304 (6)0.0230 (6)0.0058 (5)0.0047 (5)0.0006 (5)
C150.0249 (6)0.0390 (7)0.0250 (6)0.0009 (5)0.0004 (5)0.0012 (5)
C160.0316 (6)0.0290 (6)0.0255 (6)0.0064 (5)0.0026 (5)0.0012 (5)
C170.0304 (6)0.0237 (6)0.0231 (6)0.0022 (4)0.0058 (5)0.0016 (4)
C180.0433 (8)0.0278 (7)0.0374 (7)0.0023 (5)0.0016 (6)0.0038 (5)
C190.0420 (8)0.0372 (8)0.0415 (8)0.0129 (6)0.0024 (6)0.0027 (6)
Geometric parameters (Å, º) top
O1—C11.1885 (15)C9—H90.9300
O2—C11.3554 (14)C9—C101.4191 (16)
O2—C171.4127 (14)C12—H120.9300
N1—C21.3214 (15)C12—C131.3933 (17)
N1—C101.3665 (15)C12—C171.3806 (17)
C1—C21.5053 (16)C13—C141.4039 (18)
C2—C31.4118 (17)C13—C181.5045 (17)
C3—H30.9300C14—C151.3943 (18)
C3—C41.3640 (17)C14—C191.5077 (17)
C4—H40.9300C15—H150.9300
C4—C51.4132 (17)C15—C161.3918 (18)
C5—C61.4170 (17)C16—H160.9300
C5—C101.4272 (17)C16—C171.3809 (18)
C6—H60.9300C18—H18A0.9600
C6—C71.3666 (19)C18—H18B0.9600
C7—H70.9300C18—H18C0.9600
C7—C81.4122 (19)C19—H19A0.9600
C8—H80.9300C19—H19B0.9600
C8—C91.3676 (18)C19—H19C0.9600
C1—O2—C17118.28 (9)C9—C10—C5119.16 (11)
C2—N1—C10117.11 (10)C13—C12—H12120.0
O1—C1—O2124.13 (11)C17—C12—H12120.0
O1—C1—C2125.75 (11)C17—C12—C13120.08 (11)
O2—C1—C2110.12 (10)C12—C13—C14119.38 (11)
N1—C2—C1114.05 (10)C12—C13—C18120.20 (11)
N1—C2—C3124.68 (11)C14—C13—C18120.42 (11)
C3—C2—C1121.26 (10)C13—C14—C19120.60 (12)
C2—C3—H3120.7C15—C14—C13119.01 (11)
C4—C3—C2118.56 (11)C15—C14—C19120.39 (12)
C4—C3—H3120.7C14—C15—H15119.2
C3—C4—H4120.3C16—C15—C14121.67 (11)
C3—C4—C5119.46 (11)C16—C15—H15119.2
C5—C4—H4120.3C15—C16—H16121.0
C4—C5—C6123.37 (11)C17—C16—C15118.08 (11)
C4—C5—C10117.68 (11)C17—C16—H16121.0
C6—C5—C10118.95 (11)C12—C17—O2117.27 (11)
C5—C6—H6119.8C12—C17—C16121.77 (11)
C7—C6—C5120.48 (12)C16—C17—O2120.75 (11)
C7—C6—H6119.8C13—C18—H18A109.5
C6—C7—H7119.7C13—C18—H18B109.5
C6—C7—C8120.50 (12)C13—C18—H18C109.5
C8—C7—H7119.7H18A—C18—H18B109.5
C7—C8—H8119.6H18A—C18—H18C109.5
C9—C8—C7120.74 (12)H18B—C18—H18C109.5
C9—C8—H8119.6C14—C19—H19A109.5
C8—C9—H9119.9C14—C19—H19B109.5
C8—C9—C10120.13 (11)C14—C19—H19C109.5
C10—C9—H9119.9H19A—C19—H19B109.5
N1—C10—C5122.42 (10)H19A—C19—H19C109.5
N1—C10—C9118.42 (11)H19B—C19—H19C109.5
O1—C1—C2—N118.18 (18)C8—C9—C10—N1177.64 (11)
O1—C1—C2—C3162.66 (13)C8—C9—C10—C52.07 (18)
O2—C1—C2—N1160.96 (10)C10—N1—C2—C1176.20 (10)
O2—C1—C2—C318.20 (16)C10—N1—C2—C32.92 (18)
N1—C2—C3—C41.69 (19)C10—C5—C6—C70.47 (19)
C1—O2—C17—C12118.93 (12)C12—C13—C14—C150.89 (18)
C1—O2—C17—C1666.23 (14)C12—C13—C14—C19179.61 (11)
C1—C2—C3—C4177.37 (11)C13—C12—C17—O2174.15 (10)
C2—N1—C10—C51.18 (17)C13—C12—C17—C160.63 (18)
C2—N1—C10—C9178.52 (11)C13—C14—C15—C160.78 (18)
C2—C3—C4—C51.36 (18)C14—C15—C16—C170.04 (18)
C3—C4—C5—C6176.44 (12)C15—C16—C17—O2173.85 (10)
C3—C4—C5—C102.87 (18)C15—C16—C17—C120.75 (18)
C4—C5—C6—C7179.76 (12)C17—O2—C1—O11.63 (18)
C4—C5—C10—N11.64 (18)C17—O2—C1—C2177.53 (10)
C4—C5—C10—C9178.66 (11)C17—C12—C13—C140.21 (18)
C5—C6—C7—C81.0 (2)C17—C12—C13—C18178.94 (11)
C6—C5—C10—N1177.69 (11)C18—C13—C14—C15178.26 (11)
C6—C5—C10—C92.00 (18)C18—C13—C14—C191.24 (18)
C6—C7—C8—C91.0 (2)C19—C14—C15—C16179.73 (11)
C7—C8—C9—C100.58 (19)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C8—H8···O1i0.932.483.2735 (16)144
Symmetry code: (i) x, y1/2, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C8—H8···O1i0.932.483.2735 (16)143.7
Symmetry code: (i) x, y1/2, z+1/2.
 

Acknowledgements

EF thanks the CFTRI, Mysore and Yuvaraja's college, UOM for providing research facilities. EF is grateful to Mr J. R. Manjunatha, PPSFT, CFTRI for the NMR spectra. JPJ acknowledges the NSF–MRI program (grant No. CHE-1039027) for funds to purchase the X-ray diffractometer.

References

First citationAgilent (2012). CrysAlis PRO and CrysAlis RED. Agilent Technologies, Yarnton, England.
First citationAllen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.  CrossRef Web of Science
First citationButcher, R. J., Jasinski, J. P., Mayekar, A. N., Yathirajan, H. S. & Narayana, B. (2007). Acta Cryst. E63, o3603.  Web of Science CSD CrossRef IUCr Journals
First citationCampbell, S. F., Hardstone, J. D. & Palmer, M. J. (1988). J. Med. Chem. 31,1031–1035.  CrossRef CAS PubMed Web of Science
First citationDolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341.  Web of Science CrossRef CAS IUCr Journals
First citationFazal, E., Jasinski, J. P., Krauss, S. T., Sudha, B. S. & Yathirajan, H. S. (2012). Acta Cryst. E68, o3231–o3232.  CSD CrossRef CAS IUCr Journals
First citationJasinski, J. P., Butcher, R. J., Mayekar, A. N., Yathirajan, H. S., Narayana, B. & Sarojini, B. K. (2010). J. Mol. Struct. 980, 172–181.  Web of Science CSD CrossRef CAS
First citationJing, L.-H. & Qin, D.-B. (2008). Z. Kristallogr. 223, 35–36.  CAS
First citationMarkees, D. G., Dewey, V. C. & Kidder, G. W. (1970). J. Med. Chem. 13, 324–326.  CrossRef CAS PubMed Web of Science
First citationMichael, J. P. (1997). Nat. Prod. Rep. 14, 605–608.  CrossRef CAS Web of Science
First citationMorimoto, Y., Matsuda, F. & Shirahama, H. (1991). Synlett, 3, 202–203.  CrossRef
First citationPadwa, A., Brodney, M. A., Liu, B., Satake, K. & Wu, T. (1999). J. Org. Chem. 64, 3595–3607.  Web of Science CrossRef PubMed CAS
First citationPalatinus, L. & Chapuis, G. (2007). J. Appl. Cryst. 40, 786–790.  Web of Science CrossRef CAS IUCr Journals
First citationRobert, A. & Meunier, B. (1998). Chem. Soc. Rev. 27, 273–279.  Web of Science CrossRef CAS
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals
First citationSolomon, V. R. & Lee, H. (2011). Curr. Med. Chem. 18, 1488–1508.  Web of Science CAS PubMed

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 69| Part 12| December 2013| Pages o1853-o1854
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds