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

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ISSN: 2056-9890
Volume 64| Part 12| December 2008| Pages o2402-o2403

Ethyl 1-[(2-chloro-1,3-thia­zol-5-yl)methyl]-5-methyl-1H-1,2,3-triazole-4-carboxylate

aDepartment of Medicinal Chemistry, Yunyang Medical College, Shiyan, Hubei 442000, People's Republic of China, and bSchool of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang, Henan 453003, People's Republic of China
*Correspondence e-mail: chenxiaobao@yahoo.com.cn

(Received 12 November 2008; accepted 14 November 2008; online 20 November 2008)

In the title compound, C10H11ClN4O2S, the triazole ring carries methyl and ethoxy­carbonyl groups and is bound via a methyl­ene bridge to a chloro­thia­zole unit. There is also evidence for significant electron delocalization in the triazolyl system. Intra- and inter­molecular C—H⋯O hydrogen bonds together with strong ππ stacking inter­actions [centroid–centroid distance 3.620 (1) Å] stabilize the structure.

Related literature

Many derivatives of triazole have been prepared, and their biological activities have been studied by Ogura et al. (2000[Ogura, T., Numata, A., Ueno, H. & Masuzawa, Y. (2000). WO Patent 0039106.]), Najim et al. (2004[Najim, A. A., Yaseen, A. A. & Asmehan, A. (2004). Heteroat. Chem. 15, 380-387.]), Abu-Orabi et al. (1989[Abu-Orabi, S. T., Alfah, M. A., Jibril, I., Mari'i, F. M. & Ali, A. A. S. (1989). J. Heterocycl. Chem. 26, 1461-1468.]), Shuto et al. (1995[Shuto, A., Kisida, H., Tsuchiya, T., Takada, Y. & Fujimoto, H. (1995). WO Patent 9529175.]), Fan & Katritsky (1996[Fan, W.-Q. & Katritsky, A. R. (1996). Comprehensive Heterocyclic Chemistry II, Vol. 4, edited by A. R. Katrisky, C. W. Rees & E. F. V. Scriven, pp. 1-126. London, Oxford: Pergamon.]), Chen et al. (2005[Chen, W., Chen, Q., Wu, Q. Y. & Yang, G. F. (2005). Chin. J. Org. Chem. 25, 1477-1481.]) and Liu et al. (2001[Liu, Z. M., Yang, G. F. & Qing, X. H. (2001). J. Chem. Technol. Biotechnol. 76, 1154-1158.]). For the synthesis, see: Chen et al. (2007[Chen, X. B., Shi, D. Q. & Zhu, X. F. (2007). Chin. J. Chem. 25, 1854-1858.]); Chen & Shi (2008[Chen, X. B. & Shi, D. Q. (2008). Phosphorus Sulfur Silicon Relat. Elem. 183, 1134-1144.]). For bond-length data, see: Sasada (1984[Sasada, Y. (1984). Molecular and Crystal Structures in Chemistry Handbook, 3rd ed. Tokyo: The Chemical Society of Japan, Maruzen.]); Wang et al. (1998[Wang, Z., Jian, F., Duan, C., Bai, Z. & You, X. (1998). Acta Cryst. C54, 1927-1929.]). For related literature, see: Chen et al. (2007[Chen, X. B., Shi, D. Q. & Zhu, X. F. (2007). Chin. J. Chem. 25, 1854-1858.]); Tian et al. (2008[Hua, T.-J., Sun, F.-M., Liu, W.-J. & Qu, Y.-N. (2008). Acta Cryst. E64, o2351.]); Chen et al. (2008[Chen, X.-B., Sun, F.-M., Gao, H.-T., Xu, J. & Zheng, A.-H. (2008). Acta Cryst. E64, o2352.]); Knox & Rogers (1989[Knox, I. L. & Rogers, R. B. (1989). US Patent 4 775 762.]); Rogers et al. (1985[Rogers, R. B., Gerwick, B. C. & Egli, E. A. (1985). US Patent 4 474 599.]); Shuto et al. (1995[Shuto, A., Kisida, H., Tsuchiya, T., Takada, Y. & Fujimoto, H. (1995). WO Patent 9529175.]).

[Scheme 1]

Experimental

Crystal data
  • C10H11ClN4O2S

  • Mr = 286.74

  • Triclinic, [P \overline 1]

  • a = 7.9692 (14) Å

  • b = 9.1656 (16) Å

  • c = 10.4430 (18) Å

  • α = 65.892 (2)°

  • β = 67.938 (2)°

  • γ = 80.641 (2)°

  • V = 645.23 (19) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.46 mm−1

  • T = 291 (2) K

  • 0.50 × 0.40 × 0.30 mm

Data collection
  • Bruker SMART APEX CCD area-detector diffractometer

  • Absorption correction: none

  • 4630 measured reflections

  • 2332 independent reflections

  • 2005 reflections with I > 2σ(I)

  • Rint = 0.018

Refinement
  • R[F2 > 2σ(F2)] = 0.041

  • wR(F2) = 0.118

  • S = 1.04

  • 2332 reflections

  • 165 parameters

  • H-atom parameters constrained

  • Δρmax = 0.30 e Å−3

  • Δρmin = −0.25 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C2—H2⋯O1i 0.93 2.47 3.375 (4) 164
C7—H7B⋯O2 0.96 2.43 3.033 (4) 121
Symmetry code: (i) x-1, y, z.

Data collection: SMART (Bruker, 2000[Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2000[Bruker (2000). SMART and SAINT. 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: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

It is well known that many triazole-related molecules play an important role in the development of agrochemicals such as insecticides, nematocides, acaricide and plant growth regulators (Ogura et al., 2000; Najim et al., 2004; Abu-Orabi et al., 1989; Shuto et al.,1995; Fan & Katritsky, 1996; Chen et al., 2005; Richard & Ben, 1985; Ingrid et al., 1989 and Liu et al., 2001). Since the structure-activity relationship is very useful in the rational design of pharmaceuticals and agrochemicals. We report here the crystal structure of the title compound, (I) (Fig. 1), which was synthesized by introducing pyridine rings into a 1,2,3-triazole molecular framework.

In the title compound, the C5—N2 and C6—N4 bonds are significantly shorter than that of the single bond of C—N (1.47 Å; Sasada, 1984) and close to the value of the double bond of C—N (1.28 Å; Wang et al., 1998). This indicates significant electron delocalization in the triazolyl system.

Inter and intramolecular C—H···O hydrogen bonds contribute strongly to the stability of the molecular configuration (Fig.2). Strong ππ stacking interactions are also found between adjacent S1—C1/N1/C2—C3 rings with centroid-centroid distances 3.620 (1) Å, dihedral angles of 0.03 (1)°, and a shortest interplanar distance of 3.573 Å.

Related literature top

Many derivatives of triazole have been prepared, and their biological activities have been studied by Ogura et al. (2000), Najim et al. (2004), Abu-Orabi et al. (1989), Shuto et al. (1995), Fan & Katritsky (1996), Chen et al. (2005) and Liu et al. (2001). For the synthesis, see: Chen et al. (2007); Chen & Shi (2008). For bond-length data, see: Sasada (1984); Wang et al. (1998). For related literature, see: Chen et al. (2007); Ingrid & Richard (1989); Richard & Ben (1985); Shuto et al. (1995).

Experimental top

Ethyl acetylacetate (2 mmol) and 5-azidomethyl-2-chlorothiazole (2 mmol) were added to a suspension of milled potassium carbonate (2 mmol) in DMSO (10 ml). The mixture was stirred at room temperature for 6 h (monitored by thin-layer chromatography) and poured to water (50 ml). The solid was collected by filtration, washed with water and diethyl ether, respectively, and dried to give 0.52 g of the title compound (yield 91%). Colourless crystals of (I) suitable for X-ray structure analysis were grown from acetone and petroleum ether (1:1, v/v).

Refinement top

H atoms bonded to C were placed at calculated positions, with C—H distances in the range 0.93 - 0.98Å. They were refined using a riding model, with Uiso(H) = 1.2Ueq(C), or 1.5Ueq(methyl C).

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); 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 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. View of the molecular structure of (I), showing the atom labelling scheme and with displacement ellipsoids drawn at the 50% probability level.
[Figure 2] Fig. 2. A partial view of the crystal packing of (I), showing the formation of C—H···O hydrogen-bonding interactions (dashed lines).
Ethyl 1-[(2-chloro-1,3-thiazol-5-yl)methyl]-5-methyl-1H-1,2,3- triazole-4-carboxylate top
Crystal data top
C10H11ClN4O2SZ = 2
Mr = 286.74F(000) = 296
Triclinic, P1Dx = 1.476 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.9692 (14) ÅCell parameters from 2592 reflections
b = 9.1656 (16) Åθ = 2.4–27.4°
c = 10.4430 (18) ŵ = 0.46 mm1
α = 65.892 (2)°T = 291 K
β = 67.938 (2)°Block, colourless
γ = 80.641 (2)°0.50 × 0.40 × 0.30 mm
V = 645.23 (19) Å3
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer
2005 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.018
Graphite monochromatorθmax = 25.5°, θmin = 2.4°
ϕ and ω scansh = 99
4630 measured reflectionsk = 1111
2332 independent reflectionsl = 1212
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)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.118H-atom parameters constrained
S = 1.04 w = 1/[σ2(Fo2) + (0.062P)2 + 0.2829P]
where P = (Fo2 + 2Fc2)/3
2332 reflections(Δ/σ)max < 0.001
165 parametersΔρmax = 0.30 e Å3
0 restraintsΔρmin = 0.25 e Å3
Crystal data top
C10H11ClN4O2Sγ = 80.641 (2)°
Mr = 286.74V = 645.23 (19) Å3
Triclinic, P1Z = 2
a = 7.9692 (14) ÅMo Kα radiation
b = 9.1656 (16) ŵ = 0.46 mm1
c = 10.4430 (18) ÅT = 291 K
α = 65.892 (2)°0.50 × 0.40 × 0.30 mm
β = 67.938 (2)°
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer
2005 reflections with I > 2σ(I)
4630 measured reflectionsRint = 0.018
2332 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0410 restraints
wR(F2) = 0.118H-atom parameters constrained
S = 1.04Δρmax = 0.30 e Å3
2332 reflectionsΔρmin = 0.25 e Å3
165 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
Cl10.01266 (10)0.69136 (8)0.20124 (9)0.0704 (2)
S10.23526 (8)0.46808 (7)0.07021 (7)0.0534 (2)
O10.7825 (3)0.0891 (2)0.3892 (2)0.0715 (5)
O20.5259 (3)0.2272 (2)0.5002 (2)0.0718 (6)
N10.0923 (3)0.4021 (3)0.2475 (3)0.0674 (6)
N20.4074 (3)0.0929 (2)0.1275 (2)0.0486 (5)
N30.5752 (3)0.1573 (3)0.0531 (2)0.0603 (5)
N40.6709 (3)0.0880 (2)0.1400 (2)0.0567 (5)
C10.0281 (3)0.5109 (3)0.1813 (3)0.0496 (5)
C20.0196 (4)0.2725 (3)0.2086 (3)0.0676 (7)
H20.08730.18160.24460.081*
C30.1528 (3)0.2836 (3)0.1165 (3)0.0479 (5)
C40.2660 (4)0.1603 (3)0.0601 (3)0.0584 (6)
H4A0.18870.07500.08300.070*
H4B0.32220.20870.04760.070*
C50.3935 (3)0.0189 (2)0.2639 (2)0.0419 (5)
C60.5634 (3)0.0210 (2)0.2704 (2)0.0435 (5)
C70.2239 (3)0.1066 (3)0.3707 (3)0.0611 (7)
H7A0.14510.04110.42140.092*
H7B0.25210.20380.44240.092*
H7C0.16480.13140.31720.092*
C80.6388 (3)0.1135 (3)0.3903 (3)0.0472 (5)
C90.5797 (5)0.3295 (3)0.6289 (4)0.0808 (9)
H9A0.69610.29580.61630.097*
H9B0.49140.31950.71910.097*
C100.5916 (6)0.4920 (4)0.6429 (4)0.1001 (13)
H10A0.48130.52090.64270.150*
H10B0.61040.55990.73490.150*
H10C0.69130.50450.56050.150*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0673 (4)0.0627 (4)0.0875 (5)0.0081 (3)0.0224 (4)0.0417 (4)
S10.0525 (4)0.0453 (3)0.0548 (4)0.0034 (3)0.0102 (3)0.0180 (3)
O10.0572 (11)0.0679 (12)0.0968 (14)0.0051 (9)0.0423 (10)0.0223 (10)
O20.0735 (12)0.0639 (11)0.0695 (11)0.0188 (9)0.0428 (10)0.0060 (9)
N10.0479 (12)0.0600 (13)0.0824 (15)0.0036 (10)0.0144 (11)0.0218 (12)
N20.0597 (12)0.0394 (9)0.0494 (10)0.0052 (9)0.0230 (9)0.0176 (8)
N30.0638 (13)0.0530 (12)0.0515 (11)0.0068 (10)0.0123 (10)0.0125 (9)
N40.0518 (11)0.0514 (11)0.0573 (12)0.0067 (9)0.0114 (9)0.0157 (10)
C10.0496 (12)0.0485 (12)0.0504 (12)0.0045 (10)0.0207 (10)0.0174 (10)
C20.0589 (16)0.0488 (14)0.092 (2)0.0081 (12)0.0286 (14)0.0188 (14)
C30.0576 (14)0.0418 (11)0.0486 (12)0.0006 (10)0.0291 (11)0.0117 (10)
C40.0796 (17)0.0483 (13)0.0613 (15)0.0104 (12)0.0412 (13)0.0229 (12)
C50.0455 (11)0.0347 (10)0.0480 (11)0.0035 (9)0.0177 (9)0.0182 (9)
C60.0433 (11)0.0354 (10)0.0499 (12)0.0012 (9)0.0128 (9)0.0171 (9)
C70.0465 (13)0.0571 (15)0.0709 (16)0.0079 (11)0.0228 (12)0.0108 (12)
C80.0464 (12)0.0397 (11)0.0621 (14)0.0046 (10)0.0221 (10)0.0243 (10)
C90.109 (2)0.0618 (17)0.0772 (19)0.0068 (17)0.0621 (19)0.0026 (15)
C100.162 (4)0.068 (2)0.098 (2)0.034 (2)0.087 (3)0.0328 (18)
Geometric parameters (Å, º) top
Cl1—C11.715 (2)C3—C41.501 (3)
S1—C11.717 (2)C4—H4A0.9700
S1—C31.726 (2)C4—H4B0.9700
O1—C81.197 (3)C5—C61.378 (3)
O2—C81.328 (3)C5—C71.485 (3)
O2—C91.464 (3)C6—C81.476 (3)
N1—C11.281 (3)C7—H7A0.9600
N1—C21.380 (4)C7—H7B0.9600
N2—C51.349 (3)C7—H7C0.9600
N2—N31.357 (3)C9—C101.427 (5)
N2—C41.470 (3)C9—H9A0.9700
N3—N41.304 (3)C9—H9B0.9700
N4—C61.370 (3)C10—H10A0.9600
C2—C31.340 (4)C10—H10B0.9600
C2—H20.9300C10—H10C0.9600
C1—S1—C388.37 (12)C6—C5—C7133.6 (2)
C8—O2—C9118.2 (2)N4—C6—C5109.60 (19)
C1—N1—C2108.7 (2)N4—C6—C8119.0 (2)
C5—N2—N3111.70 (19)C5—C6—C8131.4 (2)
C5—N2—C4129.3 (2)C5—C7—H7A109.5
N3—N2—C4118.8 (2)C5—C7—H7B109.5
N4—N3—N2107.38 (18)H7A—C7—H7B109.5
N3—N4—C6108.2 (2)C5—C7—H7C109.5
N1—C1—Cl1122.4 (2)H7A—C7—H7C109.5
N1—C1—S1116.79 (19)H7B—C7—H7C109.5
Cl1—C1—S1120.83 (14)O1—C8—O2124.3 (2)
C3—C2—N1117.0 (2)O1—C8—C6124.5 (2)
C3—C2—H2121.5O2—C8—C6111.18 (18)
N1—C2—H2121.5C10—C9—O2110.0 (3)
C2—C3—C4128.2 (2)C10—C9—H9A109.7
C2—C3—S1109.13 (19)O2—C9—H9A109.7
C4—C3—S1122.70 (19)C10—C9—H9B109.7
N2—C4—C3111.66 (18)O2—C9—H9B109.7
N2—C4—H4A109.3H9A—C9—H9B108.2
C3—C4—H4A109.3C9—C10—H10A109.5
N2—C4—H4B109.3C9—C10—H10B109.5
C3—C4—H4B109.3H10A—C10—H10B109.5
H4A—C4—H4B107.9C9—C10—H10C109.5
N2—C5—C6103.16 (19)H10A—C10—H10C109.5
N2—C5—C7123.2 (2)H10B—C10—H10C109.5
C5—N2—N3—N40.1 (3)C4—N2—C5—C6173.8 (2)
C4—N2—N3—N4174.52 (19)N3—N2—C5—C7178.8 (2)
N2—N3—N4—C60.1 (3)C4—N2—C5—C75.1 (3)
C2—N1—C1—Cl1179.52 (19)N3—N4—C6—C50.0 (3)
C2—N1—C1—S10.5 (3)N3—N4—C6—C8178.4 (2)
C3—S1—C1—N10.1 (2)N2—C5—C6—N40.0 (2)
C3—S1—C1—Cl1179.93 (15)C7—C5—C6—N4178.6 (2)
C1—N1—C2—C30.8 (4)N2—C5—C6—C8178.2 (2)
N1—C2—C3—C4178.2 (2)C7—C5—C6—C80.4 (4)
N1—C2—C3—S10.8 (3)C9—O2—C8—O10.2 (4)
C1—S1—C3—C20.38 (19)C9—O2—C8—C6179.5 (2)
C1—S1—C3—C4178.66 (19)N4—C6—C8—O18.3 (3)
C5—N2—C4—C378.7 (3)C5—C6—C8—O1169.7 (2)
N3—N2—C4—C394.6 (3)N4—C6—C8—O2171.9 (2)
C2—C3—C4—N2109.0 (3)C5—C6—C8—O210.0 (3)
S1—C3—C4—N269.9 (3)C8—O2—C9—C10119.0 (3)
N3—N2—C5—C60.1 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C2—H2···O1i0.932.473.375 (4)164
C7—H7B···O20.962.433.033 (4)121
C9—H9A···O10.972.282.710 (4)106
Symmetry code: (i) x1, y, z.

Experimental details

Crystal data
Chemical formulaC10H11ClN4O2S
Mr286.74
Crystal system, space groupTriclinic, P1
Temperature (K)291
a, b, c (Å)7.9692 (14), 9.1656 (16), 10.4430 (18)
α, β, γ (°)65.892 (2), 67.938 (2), 80.641 (2)
V3)645.23 (19)
Z2
Radiation typeMo Kα
µ (mm1)0.46
Crystal size (mm)0.50 × 0.40 × 0.30
Data collection
DiffractometerBruker SMART APEX CCD area-detector
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
4630, 2332, 2005
Rint0.018
(sin θ/λ)max1)0.606
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.118, 1.04
No. of reflections2332
No. of parameters165
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.30, 0.25

Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C2—H2···O1i0.932.473.375 (4)164.00
C7—H7B···O20.962.433.033 (4)121.00
C9—H9A···O10.972.282.710 (4)106.00
Symmetry code: (i) x1, y, z.
 

Acknowledgements

The authors gratefully acknowledge financial support of this work by Yunyang Medical College, and acknowledge the Sophisticated Analytical Instrument Facility, Central China Normal University, Whuhan, for the data collection.

References

First citationAbu-Orabi, S. T., Alfah, M. A., Jibril, I., Mari'i, F. M. & Ali, A. A. S. (1989). J. Heterocycl. Chem. 26, 1461–1468.  CrossRef CAS Google Scholar
First citationBruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationChen, W., Chen, Q., Wu, Q. Y. & Yang, G. F. (2005). Chin. J. Org. Chem. 25, 1477–1481.  CAS Google Scholar
First citationChen, X. B. & Shi, D. Q. (2008). Phosphorus Sulfur Silicon Relat. Elem. 183, 1134–1144.  Web of Science CSD CrossRef CAS Google Scholar
First citationChen, X. B., Shi, D. Q. & Zhu, X. F. (2007). Chin. J. Chem. 25, 1854–1858.  Web of Science CSD CrossRef CAS Google Scholar
First citationChen, X.-B., Sun, F.-M., Gao, H.-T., Xu, J. & Zheng, A.-H. (2008). Acta Cryst. E64, o2352.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationFan, W.-Q. & Katritsky, A. R. (1996). Comprehensive Heterocyclic Chemistry II, Vol. 4, edited by A. R. Katrisky, C. W. Rees & E. F. V. Scriven, pp. 1–126. London, Oxford: Pergamon.  Google Scholar
First citationKnox, I. L. & Rogers, R. B. (1989). US Patent 4 775 762.  Google Scholar
First citationLiu, Z. M., Yang, G. F. & Qing, X. H. (2001). J. Chem. Technol. Biotechnol. 76, 1154–1158.  CrossRef CAS Google Scholar
First citationNajim, A. A., Yaseen, A. A. & Asmehan, A. (2004). Heteroat. Chem. 15, 380–387.  Google Scholar
First citationOgura, T., Numata, A., Ueno, H. & Masuzawa, Y. (2000). WO Patent 0039106.  Google Scholar
First citationRogers, R. B., Gerwick, B. C. & Egli, E. A. (1985). US Patent 4 474 599.  Google Scholar
First citationSasada, Y. (1984). Molecular and Crystal Structures in Chemistry Handbook, 3rd ed. Tokyo: The Chemical Society of Japan, Maruzen.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationShuto, A., Kisida, H., Tsuchiya, T., Takada, Y. & Fujimoto, H. (1995). WO Patent 9529175.  Google Scholar
First citationHua, T.-J., Sun, F.-M., Liu, W.-J. & Qu, Y.-N. (2008). Acta Cryst. E64, o2351.  Web of Science CrossRef IUCr Journals Google Scholar
First citationWang, Z., Jian, F., Duan, C., Bai, Z. & You, X. (1998). Acta Cryst. C54, 1927–1929.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar

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Volume 64| Part 12| December 2008| Pages o2402-o2403
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