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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 67| Part 3| March 2011| Page o708
doi:10.1107/S1600536811006180

2-Chloro-1-[4-(2-fluoro­benz­yl)piperazin-1-yl]ethanone

Cunlong Zhang,a,c Xin Zhai,a Furen Wan,b Ping Gonga and Yuyang Jiangc,d*

aKey Laboratory of Original New Drug Design and Discovery of the Ministry of Education, Shenyang Pharmaceutical University, Shenyang, Liaoning 110016, People's Republic of China, bDeparment of Chemistry, Northeast Normal University, Changchun 130024, People's Republic of China, cThe Key Laboratory of Chemical Biology, Guangdong Province, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, People's Republic of China, and dSchool of Medicine, Tsinghua University, Beijing 100084, People's Republic of China
*Correspondence e-mail: jiangyy@sz.tsinghua.edu.cn

(Received 5 December 2010; accepted 18 February 2011; online 26 February 2011)

In the title compound, C13H16ClFN2O, the piperazine ring is flanked by 1-(2-fluoro­benz­yl)piperazine and adopts a chair conformation. The dihedral angle between the fluoro­phenyl ring and the four planar C atoms (r.m.s. = 0.0055 Å) of the piperazine chair is 78.27 (7)°, whereas the dihedral angle between the four planar C atoms of the piperazine chair and the ethanone plane is 55.21 (9) Å; the Cl atom displaced by1.589 (2) Å out of the plane.

Related literature

For the synthesis of related compounds, see: Contreras et al. (2001[Contreras, J. M., Parrot, I., Sippl, W., Rival, Y. M. & Wermuth, C. G. (2001). J. Med. Chem. 44, 2707-2718.]); Capuano et al. (2002[Capuano, B., Crosby, I. T., Lloyd, E. J. & Taylor, D. A. (2002). Aust. J. Chem. 55, 565-576.]). For their use as inter­mediates in the synthesis of anti-inflammatory agents or CCR1 antagonists, see: Rolland & Duhault (1989[Rolland, Y. & Duhault, J. (1989). EP Patent No. 319412, 44 pp.]); Kaufmann (2005[Kaufmann, U. (2005). WO Patent No. 2005079769, 291 pp.]); Tanikawa et al. (1995[Tanikawa, K., Saito, A., Hirotsuka, M. & Shikada, K. (1995). WO Patent No. 9501343, 127 pp.]); Xie et al. (2007[Xie, Y. F., Lake, K., Ligsay, K., Komandla, M., Sircar, I., Nagarajan, G., Li, J., Xu, K., Parise, J., Schneider, L., Huang, D., Liu, J. P., Dines, K., Sakurai, N., Barbosa, M. & Jack, R. (2007). Bioorg. Med. Chem. Lett. 17, 3367-3372.]).

[Scheme 1]

Experimental

Crystal data

  • C13H16ClFN2O

  • Mr = 270.73

  • Orthorhombic, P 21 21 21

  • a = 7.9350 (5) Å

  • b = 8.4610 (4) Å

  • c = 19.0040 (11) Å

  • V = 1275.89 (12) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.30 mm−1

  • T = 291 K

  • 0.30 × 0.30 × 0.20 mm
Data collection

  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2001[Bruker (2001). SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.566, Tmax = 0.716

  • 12886 measured reflections

  • 3001 independent reflections

  • 2550 reflections with I > 2σ(I)

  • Rint = 0.033
Refinement

  • R[F2 > 2σ(F2)] = 0.035

  • wR(F2) = 0.085

  • S = 1.01

  • 3001 reflections

  • 165 parameters

  • H-atom parameters constrained

  • Δρmax = 0.33 e Å−3

  • Δρmin = −0.18 e Å−3

  • Absolute structure: Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]), 1255 Friedel pairs

  • Flack parameter: 0.03 (7)

Data collection: APEX2 (Bruker, 2003[Bruker (2003). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2001[Bruker (2001). 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: DIAMOND (Brandenburg, 1999)[Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.]; software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811006180/si2316sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811006180/si2316Isup2.hkl

checkCIF report


Comment top

Piperazine derivatives similar to the title compound are well known as being useful for a variety of pharmaceutical indication, particularly as cardiotonic, neurotropic or anti-inflammatory agents (Kaufmann, 2005). The synthesis of related pyridazine compounds and their medicinal and pharmaceutical activity were reported (Contreras et al., 2001; Capuano et al., 2002). The use of related compounds as intermediates in the synthesis of antiinflammatory agents or CCRI antagonists can be studied in various patents (Rolland & Duhault, 1989; Kaufmann, 2005; Tanikawa et al., 1995) and medicinal journal (Xie et al., 2007). Moreover, we recently identified a series of compounds bearing various substituted benzylpiperazine moiety with potent antitumor activity by virtual screening approach (paper was being revised).

Herein, we report the synthesis of the title compound as one important representative of piperazine derivatives and its X-ray crystal structure. The molecule of (I) is shown in Fig. 1. The bond lengths and angles are within normal ranges. The piperazine ring in the molecule adopts a chair conformation. The dihedral angle between the fluorophenyl ring and the four planar C atoms (r.m.s. = 0.0055 Å) of the piperazine chair is 78.27 (7)°. Whereas the dihedral angle between the four planar C atoms of the piperazine chair and the ethanone plane is 55.21 (9)Å with the Cl atom about 1.589 (2) Å out of plane. In the crystal, there are no strong intermolecular hydrogen bonds to link the molecules.

Related literature top

For the synthesis of related compounds, see: Contreras et al. (2001); Capuano et al. (2002). For their use as intermediates in the synthesis of anti-inflammatory agents or CCR1 antagonists, see: Rolland & Duhault (1989); Kaufmann (2005); Tanikawa et al. (1995); Xie et al. (2007).

Experimental top

All chemicals and solvents were obtained from commercial supplies and used without purification. To a solution of chloroacetic chloride (0.58 ml, 7.15 mmol) in CH2Cl2 (10 ml) was added, at 0 °C, 1-(2-fluorobenzyl)piperazine(II) (1.15 g, 5.90 mmol) dissolved in CH2Cl2 (20 ml) which was prepared from the reaction of anhydrous piperazine(III) and 1-(chloromethyl)-2-fluorobenzene(IV). The reaction mixture was stirred at room temperature for about 30 min until no 1-(2-fluorobenzyl)piperazine remained, as monitored by TLC. The mixture was poured into cold H2O (50 ml) and rendered alkaline with a 10% NaHCO3 aqueous solution and separated. The organic layer, dried over Na2SO4, was evaporated under reduced pressure to give 1.44 g of pure title compound as a yellow oil. Yield 90%; 1H NMR (400 MHz, CDCl3) δ 7.35 (dd, J = 7.4, 1.4 Hz, 1H), δ 7.23–7.29 (m, 1H), δ 7.12 (t, J = 7.2 Hz, 1H), δ 7.04 (t, J = 9.2 Hz, 1H), δ 4.05 (s, 2H), δ 3.64 (d, J = 5.2 Hz, 2H), δ 3.62 (d, J = 4.4 Hz, 2H), 3.52 (t, J = 5.0 Hz, 2H), δ 2.51 (dt, J = 15.6, 4.8 Hz, 4H); 13C NMR (100.6 MHz, CDCl3) δ 161.16, 131.24, 128.88, 123.88, 123.75, 115.27, 115.05, 54.87, 52.41, 52.00, 46.06, 41.93, 40.67.

Refinement top

All H atoms were positioned geometrically and refined using a riding model approximation with distances C—H = 0.93 Å for the benzene ring and 0.97 Å for Csp3 carbon atoms and Uiso(H) = 1.2 times Ueq(C). The absolute structure was determined by using the Flack parameter refinement with the TWIN/BASF instruction, and the coordinates of all atoms were inverted by instruction MOVE 1 1 1 - 1 in the final refinement with SHELXL97.

Computing details top

Data collection: APEX2 (Bruker, 2003); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound showing displacement ellipsoids at the 30% probability level.
[Figure 2] Fig. 2. Synthesis of the title compound
2-Chloro-1-[4-(2-fluorobenzyl)piperazin-1-yl]ethanone top
Crystal data top
C13H16ClFN2OF(000) = 568
Mr = 270.73Dx = 1.409 Mg m−3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71069 Å
Hall symbol: P 2ac 2abCell parameters from 25 reflections
a = 7.9350 (5) Åθ = 7.5–15°
b = 8.4610 (4) ŵ = 0.30 mm−1
c = 19.0040 (11) ÅT = 291 K
V = 1275.89 (12) Å3Block, colorless
Z = 40.30 × 0.30 × 0.20 mm
Data collection top
Bruker APEXII CCD
diffractometer		3001 independent reflections
Radiation source: fine-focus sealed tube2550 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.033
ω scansθmax = 28.4°, θmin = 3.2°
Absorption correction: multi-scan
(SADABS; Bruker, 2001)		h = −10→10
Tmin = 0.566, Tmax = 0.716k = −10→10
12886 measured reflectionsl = −25→25
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.035 w = 1/[σ2(Fo2) + (0.028P)2 + 0.4P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.085(Δ/σ)max < 0.001
S = 1.01Δρmax = 0.33 e Å−3
3001 reflectionsΔρmin = −0.18 e Å−3
165 parametersExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.077 (3)
Primary atom site location: structure-invariant direct methodsAbsolute structure: Flack (1983), 1255 Friedel pairs
Secondary atom site location: difference Fourier mapAbsolute structure parameter: 0.03 (7)
Crystal data top
C13H16ClFN2OV = 1275.89 (12) Å3
Mr = 270.73Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 7.9350 (5) ŵ = 0.30 mm−1
b = 8.4610 (4) ÅT = 291 K
c = 19.0040 (11) Å0.30 × 0.30 × 0.20 mm
Data collection top
Bruker APEXII CCD
diffractometer		3001 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2001)		2550 reflections with I > 2σ(I)
Tmin = 0.566, Tmax = 0.716Rint = 0.033
12886 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.035H-atom parameters constrained
wR(F2) = 0.085Δρmax = 0.33 e Å−3
S = 1.01Δρmin = −0.18 e Å−3
3001 reflectionsAbsolute structure: Flack (1983), 1255 Friedel pairs
165 parametersAbsolute structure parameter: 0.03 (7)
0 restraints
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
O11.51486 (16)0.40256 (17)0.67832 (8)0.0512 (3)
Cl11.23456 (9)0.09826 (6)0.64207 (3)0.06647 (19)
F10.6313 (2)0.88072 (19)0.64912 (8)0.0801 (4)
N10.96049 (18)0.62572 (16)0.64509 (8)0.0378 (3)
N21.2433 (2)0.46187 (17)0.70180 (8)0.0437 (4)
C10.8356 (2)0.8253 (2)0.56706 (9)0.0415 (4)
C20.7317 (3)0.9332 (2)0.59859 (10)0.0492 (5)
C30.7224 (3)1.0901 (3)0.58058 (12)0.0622 (6)
H30.64971.15820.60410.075*
C40.8215 (3)1.1433 (3)0.52783 (12)0.0623 (6)
H40.81771.24910.51460.075*
C50.9276 (3)1.0405 (3)0.49380 (12)0.0588 (6)
H50.99601.07660.45740.071*
C60.9328 (3)0.8832 (3)0.51363 (10)0.0524 (5)
H61.00470.81480.48980.063*
C70.8427 (2)0.6546 (2)0.58860 (10)0.0459 (4)
H7A0.73120.62110.60340.055*
H7B0.87460.59120.54820.055*
C81.1333 (2)0.6613 (2)0.62433 (10)0.0424 (4)
H8A1.14090.77230.61180.051*
H8B1.16130.60000.58280.051*
C91.2590 (2)0.6266 (2)0.68052 (10)0.0459 (4)
H9A1.37190.64640.66310.055*
H9B1.23950.69510.72070.055*
C101.0718 (2)0.4225 (3)0.72213 (11)0.0500 (5)
H10A1.04130.48210.76380.060*
H10B1.06550.31090.73360.060*
C110.9506 (2)0.4583 (2)0.66487 (11)0.0460 (5)
H11A0.97580.39310.62420.055*
H11B0.83720.43370.68040.055*
C121.3729 (2)0.3613 (2)0.69620 (9)0.0388 (4)
C131.3417 (3)0.1882 (2)0.71208 (10)0.0476 (5)
H13A1.27530.17870.75470.057*
H13B1.44840.13510.71970.057*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0326 (7)0.0537 (8)0.0671 (9)0.0000 (6)−0.0001 (6)0.0034 (7)
Cl10.0760 (4)0.0506 (3)0.0729 (3)−0.0109 (3)−0.0059 (3)−0.0099 (3)
F10.0805 (10)0.0910 (10)0.0688 (8)0.0264 (8)0.0272 (8)0.0187 (8)
N10.0326 (7)0.0339 (7)0.0471 (8)0.0024 (6)−0.0027 (6)0.0003 (6)
N20.0343 (8)0.0416 (7)0.0552 (9)0.0042 (7)0.0010 (8)0.0090 (6)
C10.0373 (9)0.0480 (10)0.0393 (9)0.0030 (8)−0.0091 (7)−0.0007 (8)
C20.0465 (11)0.0587 (12)0.0423 (9)0.0063 (10)−0.0002 (9)0.0045 (8)
C30.0751 (15)0.0544 (11)0.0573 (12)0.0190 (12)0.0006 (12)−0.0014 (10)
C40.0801 (17)0.0479 (12)0.0590 (13)−0.0008 (11)−0.0167 (11)0.0099 (10)
C50.0596 (14)0.0677 (14)0.0492 (11)−0.0068 (11)−0.0017 (10)0.0128 (10)
C60.0502 (11)0.0624 (13)0.0447 (10)0.0049 (10)−0.0006 (9)−0.0006 (10)
C70.0400 (10)0.0464 (10)0.0512 (10)−0.0017 (8)−0.0089 (9)−0.0047 (9)
C80.0363 (9)0.0337 (8)0.0570 (11)−0.0023 (7)−0.0006 (8)0.0053 (8)
C90.0370 (9)0.0362 (9)0.0645 (11)−0.0006 (8)−0.0076 (9)0.0016 (8)
C100.0393 (11)0.0497 (11)0.0610 (12)0.0068 (8)0.0094 (9)0.0158 (10)
C110.0328 (9)0.0397 (9)0.0656 (13)−0.0015 (8)0.0056 (9)0.0061 (9)
C120.0364 (9)0.0433 (9)0.0366 (8)0.0023 (8)−0.0050 (7)−0.0010 (7)
C130.0479 (11)0.0442 (11)0.0506 (11)0.0067 (9)−0.0049 (9)0.0071 (9)
Geometric parameters (Å, º) top
O1—C121.228 (2)C5—H50.9300
Cl1—C131.753 (2)C6—H60.9300
F1—C21.324 (2)C7—H7A0.9700
N1—C71.444 (2)C7—H7B0.9700
N1—C81.459 (2)C8—C91.490 (3)
N1—C111.467 (2)C8—H8A0.9700
N2—C121.339 (2)C8—H8B0.9700
N2—C101.454 (2)C9—H9A0.9700
N2—C91.457 (2)C9—H9B0.9700
C1—C61.366 (3)C10—C111.483 (3)
C1—C21.369 (3)C10—H10A0.9700
C1—C71.502 (3)C10—H10B0.9700
C2—C31.373 (3)C11—H11A0.9700
C3—C41.351 (3)C11—H11B0.9700
C3—H30.9300C12—C131.515 (3)
C4—C51.373 (3)C13—H13A0.9700
C4—H40.9300C13—H13B0.9700
C5—C61.384 (3)
C7—N1—C8111.87 (15)C9—C8—H8A108.9
C7—N1—C11108.62 (14)N1—C8—H8B108.9
C8—N1—C11108.59 (13)C9—C8—H8B108.9
C12—N2—C10126.45 (15)H8A—C8—H8B107.7
C12—N2—C9121.38 (16)N2—C9—C8109.27 (15)
C10—N2—C9111.92 (15)N2—C9—H9A109.8
C6—C1—C2115.21 (18)C8—C9—H9A109.8
C6—C1—C7121.77 (18)N2—C9—H9B109.8
C2—C1—C7123.02 (18)C8—C9—H9B109.8
F1—C2—C1117.11 (18)H9A—C9—H9B108.3
F1—C2—C3118.22 (19)N2—C10—C11111.40 (16)
C1—C2—C3124.7 (2)N2—C10—H10A109.3
C4—C3—C2118.4 (2)C11—C10—H10A109.3
C4—C3—H3120.8N2—C10—H10B109.3
C2—C3—H3120.8C11—C10—H10B109.3
C3—C4—C5119.7 (2)H10A—C10—H10B108.0
C3—C4—H4120.2N1—C11—C10110.55 (16)
C5—C4—H4120.2N1—C11—H11A109.5
C4—C5—C6120.0 (2)C10—C11—H11A109.5
C4—C5—H5120.0N1—C11—H11B109.5
C6—C5—H5120.0C10—C11—H11B109.5
C1—C6—C5122.1 (2)H11A—C11—H11B108.1
C1—C6—H6119.0O1—C12—N2123.07 (18)
C5—C6—H6119.0O1—C12—C13118.68 (17)
N1—C7—C1112.92 (15)N2—C12—C13118.24 (17)
N1—C7—H7A109.0C12—C13—Cl1110.34 (13)
C1—C7—H7A109.0C12—C13—H13A109.6
N1—C7—H7B109.0Cl1—C13—H13A109.6
C1—C7—H7B109.0C12—C13—H13B109.6
H7A—C7—H7B107.8Cl1—C13—H13B109.6
N1—C8—C9113.25 (16)H13A—C13—H13B108.1
N1—C8—H8A108.9
C6—C1—C2—F1177.86 (18)C11—N1—C8—C9−57.8 (2)
C7—C1—C2—F1−1.6 (3)C12—N2—C9—C8120.59 (19)
C6—C1—C2—C3−0.9 (3)C10—N2—C9—C8−54.0 (2)
C7—C1—C2—C3179.7 (2)N1—C8—C9—N256.1 (2)
F1—C2—C3—C4−178.3 (2)C12—N2—C10—C11−118.1 (2)
C1—C2—C3—C40.4 (3)C9—N2—C10—C1156.2 (2)
C2—C3—C4—C50.1 (3)C7—N1—C11—C10179.10 (16)
C3—C4—C5—C60.0 (3)C8—N1—C11—C1057.2 (2)
C2—C1—C6—C50.9 (3)N2—C10—C11—N1−57.6 (2)
C7—C1—C6—C5−179.60 (19)C10—N2—C12—O1179.59 (18)
C4—C5—C6—C1−0.5 (3)C9—N2—C12—O15.8 (3)
C8—N1—C7—C1−63.4 (2)C10—N2—C12—C130.2 (3)
C11—N1—C7—C1176.72 (16)C9—N2—C12—C13−173.64 (16)
C6—C1—C7—N193.1 (2)O1—C12—C13—Cl1−103.48 (18)
C2—C1—C7—N1−87.4 (2)N2—C12—C13—Cl175.97 (19)
C7—N1—C8—C9−177.68 (15)

Experimental details

Crystal data
Chemical formulaC13H16ClFN2O
Mr270.73
Crystal system, space groupOrthorhombic, P212121
Temperature (K)291
a, b, c (Å)7.9350 (5), 8.4610 (4), 19.0040 (11)
V (Å3)1275.89 (12)
Z4
Radiation typeMo Kα
µ (mm−1)0.30
Crystal size (mm)0.30 × 0.30 × 0.20
Data collection
DiffractometerBruker APEXII CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2001)
Tmin, Tmax0.566, 0.716
No. of measured, independent and
observed [I > 2σ(I)] reflections		12886, 3001, 2550
Rint0.033
(sin θ/λ)max (Å−1)0.668
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.035, 0.085, 1.01
No. of reflections3001
No. of parameters165
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.33, −0.18
Absolute structureFlack (1983), 1255 Friedel pairs
Absolute structure parameter0.03 (7)

Computer programs: APEX2 (Bruker, 2003), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 1999).

 

Acknowledgements

The authors would like to thank the Ministry of Science and Technology of China (2007AA02Z160, 2009ZX09501–004) and the Chinese National Natural Science Foundation (20872077, 90813013) for financial support.

References

First citationBrandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
 First citationBruker (2001). SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationBruker (2003). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationCapuano, B., Crosby, I. T., Lloyd, E. J. & Taylor, D. A. (2002). Aust. J. Chem. 55, 565–576.  Web of Science CrossRef CAS Google Scholar
 First citationContreras, J. M., Parrot, I., Sippl, W., Rival, Y. M. & Wermuth, C. G. (2001). J. Med. Chem. 44, 2707–2718.  Web of Science CrossRef PubMed CAS Google Scholar
 First citationFlack, H. D. (1983). Acta Cryst. A39, 876–881.  CrossRef CAS Web of Science IUCr Journals Google Scholar
 First citationKaufmann, U. (2005). WO Patent No. 2005079769, 291 pp.  Google Scholar
 First citationRolland, Y. & Duhault, J. (1989). EP Patent No. 319412, 44 pp.  Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationTanikawa, K., Saito, A., Hirotsuka, M. & Shikada, K. (1995). WO Patent No. 9501343, 127 pp.  Google Scholar
 First citationXie, Y. F., Lake, K., Ligsay, K., Komandla, M., Sircar, I., Nagarajan, G., Li, J., Xu, K., Parise, J., Schneider, L., Huang, D., Liu, J. P., Dines, K., Sakurai, N., Barbosa, M. & Jack, R. (2007). Bioorg. Med. Chem. Lett. 17, 3367–3372.  Web of Science CrossRef PubMed CAS Google Scholar

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ISSN: 2056-9890
Volume 67| Part 3| March 2011| Page o708
doi:10.1107/S1600536811006180
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