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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 68| Part 12| December 2012| Pages o3400-o3401

Methyl 2-(3-chloro­benzamido)­benzoate

aLaboratoire de Chimie Bio-organique et Macromoléculaire, Faculté des Sciences et Techniques Guéliz, Marrakech, Morocco, bUnité de Chimie Biomoléculaire et Médicinale, Faculté des Sciences Semlalia, Marrakech, Morocco, cLaboratoire de la Matière Condensée et des Nanostructures, Faculté des Sciences et Techniques Guéliz, Marrakech, Morocco, and dLaboratoire de Chimie du Solide Appliquée, Faculté des Sciences, Université Mohammed V-Agdal, Avenue Ibn Battouta, BP 1014, Rabat, Morocco
*Correspondence e-mail: a_ouahrouch@yahoo.fr

(Received 6 November 2012; accepted 14 November 2012; online 24 November 2012)

In the mol­ecule of the title compound, C15H12ClNO3, the chloro­benzamide and benzoate units are almost co-planar, with a dihedral angle between the six-membered rings of 2.99 (10)°. An intra­molecular N—H⋯O hydrogen bond occurs. In the crystal, each mol­ecule is linked to a symmetry-equivalent counterpart across a twofold rotation axis by weak C—H⋯O and C—H⋯Cl hydrogen bonds, forming dimers. The packing is stabilized through weak ππ stacking along the b-axis direction, leading to π-stacked columns of inversion-related mol­ecules, with an inter­planar distance of 3.46 (2) Å and a centroid–centroid vector of 3.897 (2) Å.

Related literature

For details of the synthesis, see: Shariat & Abdollahi (2004[Shariat, M. & Abdollahi, S. (2004). Molecules, 9, 705-712.]); Xingwen et al. (2007[Xingwen, G., Xuejian, C., Kai, Y., Baoan, S., Lili, G. & Zhuo, C. (2007). Molecules, 12, 2621-2642.]); Chandrika et al. (2008[Chandrika, P. M., Yakaiah, T., Raghu Ram Rao, A., Narsaiah, B., Chakra Reddy, N., Sridhar, V. & Venkateshwara Rao, J. (2008). Eur. J. Med. Chem. 43, 846-852.]). For background to the potential biological use of benzoxazinone derivatives, see: Kurosaki & Naishi (1983[Kurosaki, F. & Naishi, A. (1983). Phytochemistry, 22, 669-672.]); Ponchet et al. (1988[Ponchet, M., Favre-Bonvin, J., Hauteville, M. & Ricci, P. (1988). Phytochemistry, 27, 725-730.]); Hedsrom et al. (1984[Hedsrom, L., Moorman, A. R., Dobbs, J. & Abeles, R. H. (1984). Biochemistry, 23, 1753-1759.]); Krantz et al. (1990[Krantz, A., Spencer, R. W., Tam, T. F., Liak, T. J., Copp, L. J., Thomas, E. M. & Rafferty, S. P. (1990). J. Med. Chem. 33, 464-479.]).

[Scheme 1]

Experimental

Crystal data
  • C15H12ClNO3

  • Mr = 289.71

  • Monoclinic, C 2/c

  • a = 25.7464 (10) Å

  • b = 6.9203 (2) Å

  • c = 16.9735 (6) Å

  • β = 116.045 (2)°

  • V = 2717.10 (16) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 0.29 mm−1

  • T = 296 K

  • 0.36 × 0.31 × 0.27 mm

Data collection
  • Bruker X8 APEXII diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.957, Tmax = 0.997

  • 20126 measured reflections

  • 3511 independent reflections

  • 2143 reflections with I > 2σ(I)

  • Rint = 0.038

Refinement
  • R[F2 > 2σ(F2)] = 0.047

  • wR(F2) = 0.144

  • S = 1.02

  • 3511 reflections

  • 181 parameters

  • H-atom parameters constrained

  • Δρmax = 0.31 e Å−3

  • Δρmin = −0.40 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H2⋯O2 0.86 1.96 2.6506 (19) 137
C1—H1⋯O1i 0.93 2.67 3.573 (2) 163
C9—H9⋯Cl1i 0.93 2.87 3.617 (2) 139
Symmetry code: (i) [-x+2, y, -z+{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]) and Mercury (Macrae et al. 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]); software used to prepare material for publication: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Comment top

Benzoxazinone derivatives were found to be inhibitors of standard serine proteases of the chrymotrypsin superfamily (Kurosaki & Naishi, 1983, Ponchet et al., 1988) and inhibit by formation of an acyl-enzyme complex through attack of the active site serine on the carbonyl group (Hedsrom et al., 1984, Krantz et al., 1990). The benzoxazinone derivatives have two available sites for nucleophilic attack. The two sites have partial positive charges that can guide different types of nucleophiles towards the opening of the heterocyles of the benzoxazinone derivatives. In general, benzoxazinone derivatives show good reactivity towards substitution reactions at position number 2 of the heterocycle and at positions 5, 6, 7 and 8 of the aromatic ring (Shariat & Abdollahi 2004). In connection to our studies on the synthesis of new bis-hyterocyclic compounds with different substituents, we decided to attempt to open the benzoxazinone heterocycle under basic conditions. Ring opening of 2-(3-chlorophenyl)-benzo[d][1,3] oxazin-4-one with potassium carbonate in methanol yielded the title compound.

The crystal structure of the methyl-2-(3-chlorobenzamido)benzoate features two aromatic six-membered rings (C1 to C6 and C8 to C13) which are, as expected, virtually planar, with maximum deviations of 0.006 (2) Å and -0.004 (2) Å for C1 and C9, respectively as shown in Fig.1. Moreover, the two rings are nearly coplanar as indicated by the dihedral angle between them of 2.99 (10) °. The two rings are linked through a connecting amide group with a C6—C7—N1—C8 dihedral angle of 174.71 (17)° (anti-periplanar conformation).

The cohesion of the molecules in the crystal structure is ensured by C1—H1···O1 and C9—H9···Cl1 non classic weak hydrogen bonds between symmetry equivalent molecules across a twofold rotation axis, forming dimers (Fig.2 and Table 2, symmetry operator (i) -x+2, y, -z+1/2). The structure is further stabilized by weak ππ stacking interactions between inversion-related molecules (symmetry operator (ii) -x+2, -y+1, -z+1), with an interplanar distance of 3.46 (2) Å and a centroid–centroid vector of 3.897 (2) Å, leading to formation of π-stacked columns of inversion-related molecules along the direction of the b-axis.

Related literature top

For details of the synthesis, see: Shariat & Abdollahi (2004); Xingwen et al. (2007); Chandrika et al. (2008). For background to the potential biological use of benzoxazinone derivatives, see: Kurosaki & Naishi (1983); Ponchet et al. (1988); Hedsrom et al. (1984); Krantz et al. (1990).

Experimental top

In the first step, follwowing a literature procedure (Xingwen et al., 2007; Chandrika et al., 2008) anthranilic acid (2-amino benzoic acid) was reacted with benzoyl chloride in dry pyridine at 273 K for 4 h to obtain 2-(3-chlorophenyl)-benzo[d][1,3] oxazin-4-one in good yield (75%). This products was then mixed with 0.5 eq of potassium carbonate in methanol to form the title compound in close to quantitative yield. The crude product was purified by passing through a column packed with silica gel. The solvent used for column chromatography was methylene chloride. A colourless crystal suitable for X-ray analysis was obtained by slow evaporation of a solution in methanol. The compound was characterized by 1H and 13C NMR and its structure was confirmed by X-ray diffraction analysis. 1H NMR (300 MHz, CDCl3) δ (ppm): 3.95 (s, 3H, -OCH3), 7.08-7.14 (m, 1H, H-Aromatic), 7.40-7.61 (m, 3H, H-Aromatic), 7.86 (d, 1H, H-Aromatic), 8.02-8.07 (m, 2H, H-Aromatic), 8.85 (m, 1H, H-Aromatic), 11.90 (s, 1H, -NH-). 13C NMR (300 MHz, CDCl3) δ (ppm): 52.54 (-OCH3), 120.47, 122.89, 125.10, 128.05, 130.05, 130.98, 131.94, 134.84 (CH-Aromatic), 115.28, 135.10, 136.71, 141.56 (C-Aromatic), 164.45 (CO), 169.05 (CO).

Refinement top

H atoms were located in a difference map and treated as riding with C—H = 0.96 Å, C—H = 0.97 Å, C—H = 0.93 Å and N—H = 0.86 Å for methyl, methylene, aromatic CH and NH respectively. All hydrogen atoms were refined with Uiso(H) = 1.2 Ueq (aromatic, methylene) or Uiso(H) = 1.5 Ueq for methyl.

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae et al. 2008); software used to prepare material for publication: PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound with the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small circles.
[Figure 2] Fig. 2. Packing of molecules through hydrogen bonds and π-stacking. Symmetry codes:(') -x+2, y, -z+1/2; (") -x+2, -y+1, -z+1.
Methyl 2-(3-chlorobenzamido)benzoate top
Crystal data top
C15H12ClNO3F(000) = 1200
Mr = 289.71Dx = 1.416 Mg m3
Monoclinic, C2/cMelting point: 361.5 K
Hall symbol: -c 2ycMo Kα radiation, λ = 0.71073 Å
a = 25.7464 (10) ÅCell parameters from 3511 reflections
b = 6.9203 (2) Åθ = 3.1–28.7°
c = 16.9735 (6) ŵ = 0.29 mm1
β = 116.045 (2)°T = 296 K
V = 2717.10 (16) Å3Block, colourless
Z = 80.36 × 0.31 × 0.27 mm
Data collection top
Bruker X8 APEXII
diffractometer
3511 independent reflections
Radiation source: fine-focus sealed tube2143 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.038
ϕ and ω scansθmax = 28.7°, θmin = 3.1°
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
h = 3434
Tmin = 0.957, Tmax = 0.997k = 69
20126 measured reflectionsl = 2222
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.047Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.144H-atom parameters constrained
S = 1.02 w = 1/[σ2(Fo2) + (0.0663P)2 + 1.0088P]
where P = (Fo2 + 2Fc2)/3
3511 reflections(Δ/σ)max = 0.001
181 parametersΔρmax = 0.31 e Å3
0 restraintsΔρmin = 0.40 e Å3
Crystal data top
C15H12ClNO3V = 2717.10 (16) Å3
Mr = 289.71Z = 8
Monoclinic, C2/cMo Kα radiation
a = 25.7464 (10) ŵ = 0.29 mm1
b = 6.9203 (2) ÅT = 296 K
c = 16.9735 (6) Å0.36 × 0.31 × 0.27 mm
β = 116.045 (2)°
Data collection top
Bruker X8 APEXII
diffractometer
3511 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
2143 reflections with I > 2σ(I)
Tmin = 0.957, Tmax = 0.997Rint = 0.038
20126 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0470 restraints
wR(F2) = 0.144H-atom parameters constrained
S = 1.02Δρmax = 0.31 e Å3
3511 reflectionsΔρmin = 0.40 e Å3
181 parameters
Special details top

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

Refinement. Refinement of F2 against all reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on all data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C11.07779 (8)0.3043 (3)0.40699 (12)0.0493 (4)
H11.06010.30840.34600.059*
C21.13694 (8)0.3154 (3)0.45261 (13)0.0532 (5)
C31.16464 (8)0.3122 (3)0.54250 (13)0.0576 (5)
H31.20470.31990.57200.069*
C41.13189 (9)0.2973 (3)0.58835 (13)0.0598 (5)
H41.15000.29620.64930.072*
C51.07250 (8)0.2840 (3)0.54427 (12)0.0523 (5)
H51.05080.27320.57580.063*
C61.04473 (7)0.2867 (2)0.45306 (11)0.0450 (4)
C70.98059 (8)0.2750 (3)0.40006 (12)0.0491 (4)
C80.89076 (8)0.2154 (3)0.41741 (12)0.0479 (4)
C90.85177 (9)0.2244 (3)0.32896 (13)0.0643 (6)
H90.86530.23540.28650.077*
C100.79331 (9)0.2169 (4)0.30448 (14)0.0770 (7)
H100.76770.22450.24530.092*
C110.77171 (9)0.1984 (4)0.36551 (15)0.0751 (7)
H110.73210.19320.34790.090*
C120.80976 (8)0.1878 (3)0.45261 (14)0.0613 (5)
H120.79550.17430.49400.074*
C130.86918 (8)0.1966 (3)0.48050 (11)0.0470 (4)
C140.90870 (8)0.1895 (3)0.57552 (12)0.0497 (4)
C150.91577 (12)0.1812 (5)0.71856 (14)0.0935 (9)
H15A0.89210.15090.74760.112*
H15B0.93330.30570.73750.112*
H15C0.94540.08510.73270.112*
N10.95046 (6)0.2249 (2)0.44555 (10)0.0496 (4)
H20.97120.19460.49960.060*
O10.95798 (6)0.3078 (3)0.32160 (9)0.0813 (5)
O20.96083 (6)0.1874 (2)0.60722 (8)0.0627 (4)
O30.88031 (6)0.1841 (2)0.62469 (9)0.0710 (4)
Cl11.17831 (2)0.33637 (11)0.39517 (4)0.0870 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0453 (10)0.0606 (11)0.0458 (10)0.0014 (8)0.0234 (8)0.0021 (8)
C20.0452 (10)0.0637 (12)0.0583 (11)0.0011 (8)0.0298 (9)0.0003 (9)
C30.0397 (10)0.0745 (13)0.0562 (11)0.0021 (9)0.0190 (9)0.0015 (9)
C40.0485 (11)0.0805 (14)0.0461 (11)0.0045 (10)0.0169 (9)0.0017 (9)
C50.0454 (11)0.0680 (12)0.0473 (10)0.0040 (9)0.0238 (9)0.0012 (8)
C60.0406 (9)0.0493 (9)0.0479 (10)0.0006 (7)0.0219 (8)0.0016 (8)
C70.0439 (10)0.0626 (11)0.0445 (10)0.0023 (8)0.0228 (8)0.0027 (8)
C80.0378 (9)0.0596 (11)0.0458 (10)0.0027 (8)0.0178 (8)0.0009 (8)
C90.0446 (11)0.1000 (16)0.0459 (11)0.0092 (11)0.0175 (9)0.0012 (10)
C100.0443 (12)0.123 (2)0.0511 (12)0.0117 (12)0.0092 (10)0.0035 (12)
C110.0351 (10)0.1150 (19)0.0692 (14)0.0091 (11)0.0173 (10)0.0055 (13)
C120.0434 (11)0.0823 (14)0.0628 (12)0.0034 (10)0.0276 (10)0.0032 (11)
C130.0405 (10)0.0532 (10)0.0479 (10)0.0017 (8)0.0198 (8)0.0001 (8)
C140.0472 (11)0.0575 (11)0.0495 (10)0.0008 (8)0.0259 (9)0.0026 (8)
C150.0829 (18)0.157 (3)0.0497 (13)0.0046 (17)0.0375 (13)0.0061 (14)
N10.0364 (8)0.0701 (10)0.0430 (8)0.0001 (7)0.0180 (7)0.0044 (7)
O10.0493 (9)0.1499 (15)0.0442 (8)0.0092 (9)0.0199 (7)0.0100 (8)
O20.0461 (8)0.0951 (11)0.0464 (7)0.0013 (7)0.0198 (6)0.0058 (7)
O30.0586 (9)0.1105 (12)0.0529 (8)0.0034 (8)0.0326 (7)0.0034 (7)
Cl10.0521 (3)0.1486 (7)0.0740 (4)0.0057 (3)0.0405 (3)0.0009 (4)
Geometric parameters (Å, º) top
C1—C21.374 (3)C9—C101.375 (3)
C1—C61.391 (2)C9—H90.9300
C1—H10.9300C10—C111.380 (3)
C2—C31.372 (3)C10—H100.9300
C2—Cl11.7374 (18)C11—C121.371 (3)
C3—C41.380 (3)C11—H110.9300
C3—H30.9300C12—C131.390 (3)
C4—C51.379 (3)C12—H120.9300
C4—H40.9300C13—C141.482 (3)
C5—C61.392 (3)C14—O21.207 (2)
C5—H50.9300C14—O31.329 (2)
C6—C71.496 (3)C15—O31.448 (3)
C7—O11.218 (2)C15—H15A0.9600
C7—N11.358 (2)C15—H15B0.9600
C8—C91.394 (3)C15—H15C0.9600
C8—N11.397 (2)N1—H20.8600
C8—C131.412 (2)
C2—C1—C6119.22 (17)C8—C9—H9120.0
C2—C1—H1120.4C9—C10—C11121.7 (2)
C6—C1—H1120.4C9—C10—H10119.2
C3—C2—C1122.16 (17)C11—C10—H10119.2
C3—C2—Cl1118.55 (15)C12—C11—C10118.80 (19)
C1—C2—Cl1119.28 (15)C12—C11—H11120.6
C2—C3—C4118.71 (18)C10—C11—H11120.6
C2—C3—H3120.6C11—C12—C13121.57 (19)
C4—C3—H3120.6C11—C12—H12119.2
C5—C4—C3120.37 (18)C13—C12—H12119.2
C5—C4—H4119.8C12—C13—C8119.09 (17)
C3—C4—H4119.8C12—C13—C14119.73 (16)
C4—C5—C6120.56 (17)C8—C13—C14121.17 (16)
C4—C5—H5119.7O2—C14—O3122.00 (17)
C6—C5—H5119.7O2—C14—C13125.66 (16)
C1—C6—C5118.96 (16)O3—C14—C13112.34 (16)
C1—C6—C7116.94 (16)O3—C15—H15A109.5
C5—C6—C7124.09 (16)O3—C15—H15B109.5
O1—C7—N1123.45 (17)H15A—C15—H15B109.5
O1—C7—C6121.25 (16)O3—C15—H15C109.5
N1—C7—C6115.29 (16)H15A—C15—H15C109.5
C9—C8—N1122.04 (16)H15B—C15—H15C109.5
C9—C8—C13118.94 (17)C7—N1—C8129.44 (16)
N1—C8—C13119.03 (15)C7—N1—H2115.3
C10—C9—C8119.93 (19)C8—N1—H2115.3
C10—C9—H9120.0C14—O3—C15115.88 (17)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H2···O20.861.962.6506 (19)137
C1—H1···O1i0.932.673.573 (2)163
C9—H9···Cl1i0.932.873.617 (2)139
Symmetry code: (i) x+2, y, z+1/2.

Experimental details

Crystal data
Chemical formulaC15H12ClNO3
Mr289.71
Crystal system, space groupMonoclinic, C2/c
Temperature (K)296
a, b, c (Å)25.7464 (10), 6.9203 (2), 16.9735 (6)
β (°) 116.045 (2)
V3)2717.10 (16)
Z8
Radiation typeMo Kα
µ (mm1)0.29
Crystal size (mm)0.36 × 0.31 × 0.27
Data collection
DiffractometerBruker X8 APEXII
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.957, 0.997
No. of measured, independent and
observed [I > 2σ(I)] reflections
20126, 3511, 2143
Rint0.038
(sin θ/λ)max1)0.676
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.047, 0.144, 1.02
No. of reflections3511
No. of parameters181
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.31, 0.40

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae et al. 2008), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H2···O20.861.962.6506 (19)136.6
C1—H1···O1i0.932.673.573 (2)162.7
C9—H9···Cl1i0.932.873.617 (2)138.6
Symmetry code: (i) x+2, y, z+1/2.
 

Acknowledgements

The authors thank the Unit of Support for Technical and Scientific Research (UATRS, CNRST) for the X-ray measurements.

References

First citationBruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationChandrika, P. M., Yakaiah, T., Raghu Ram Rao, A., Narsaiah, B., Chakra Reddy, N., Sridhar, V. & Venkateshwara Rao, J. (2008). Eur. J. Med. Chem. 43, 846–852.  Web of Science CrossRef PubMed CAS Google Scholar
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationHedsrom, L., Moorman, A. R., Dobbs, J. & Abeles, R. H. (1984). Biochemistry, 23, 1753–1759.  PubMed Web of Science Google Scholar
First citationKrantz, A., Spencer, R. W., Tam, T. F., Liak, T. J., Copp, L. J., Thomas, E. M. & Rafferty, S. P. (1990). J. Med. Chem. 33, 464–479.  CrossRef CAS PubMed Web of Science Google Scholar
First citationKurosaki, F. & Naishi, A. (1983). Phytochemistry, 22, 669–672.  CrossRef CAS Web of Science Google Scholar
First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationPonchet, M., Favre-Bonvin, J., Hauteville, M. & Ricci, P. (1988). Phytochemistry, 27, 725–730.  CrossRef CAS Web of Science Google Scholar
First citationShariat, M. & Abdollahi, S. (2004). Molecules, 9, 705–712.  Web of Science CrossRef PubMed CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationXingwen, G., Xuejian, C., Kai, Y., Baoan, S., Lili, G. & Zhuo, C. (2007). Molecules, 12, 2621–2642.  Web of Science PubMed Google Scholar

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 68| Part 12| December 2012| Pages o3400-o3401
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds