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

Journal logoIUCrDATA
ISSN: 2414-3146

Di­ethyl 1-[(4-methyl-2-phenyl-4,5-di­hydro-1,3-oxazol-4-yl)meth­yl]-1H-1,2,3-triazole-4,5-di­carboxyl­ate

CROSSMARK_Color_square_no_text.svg

aFormation Doctorale Molécules Bioactives, Santé et Biotechnologies, Centre détudes Doctorales Sciences et Technologies, Faculté des Sciences Dhar El Marhaz, Fès, Morocco, bLaboratoire de Chimie Organique, Faculté des Sciences Dhar el Mahraz, Université Sidi Mohammed Ben Abdellah, Fès, Morocco, and cLaboratoire de Chimie des Matériaux et Biotechnologie des Produits Naturels, E.Ma.Me.P.S., Université Moulay Ismail, Faculté des Sciences, Meknès, Morocco
*Correspondence e-mail: anouar.alami@usmba.ac.ma

Edited by E. R. T. Tiekink, Sunway University, Malaysia (Received 10 November 2017; accepted 26 November 2017; online 28 November 2017)

In the title compound, C19H22N4O5, the central triazole ring makes dihedral angles of 56.15 (8) and 43.25 (9)° with the oxazole and benzene rings, respectively. The mean planes of the two eth­oxy­carbonyl groups make dihedral angles of 24.16 (11) and 51.90 (10)° with the triazole ring. Globally, the mol­ecule has a U-shape. In the crystal, mol­ecules are linked by C—H⋯O and C—H⋯N hydrogen bonds into supra­molecular layers in the bc plane.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

Azide–alkyne cyclo­addition is a useful and convenient method for the preparation of 1,2,3-triazoles (Lutz et al., 2008[Lutz, J. F. (2008). Angew. Chem. Int. Ed. 47, 2182-2184.]; Oliva et al., 2008[Oliva, A. I., Christmann, U., Font, D., Cuevas, F., Ballester, P., Buschmann, H., Torrens, A., Yenes, S. & Pericàs, M. A. (2008). Org. Lett. 10, 1617-1619.]; Kiss et al., 2010[Kiss, L., Forró, E., Sillanpää, R. & Fülöp, F. (2010). Tetrahedron, 66, 3599-3607.]). The approach for the synthesis of 1,2,3-triazole-substituted compounds involves transformation of the azide function in a 1,3-dipolar cyclo­addition reaction with acetyl­ene derivatives. In this context, the title compound was obtained with good yield (Boukhssas et al., 2017[Boukhssas, S., Aouine, Y., Faraj, H., Alami, A., El Hallaoui, A. & Bekkari, H. (2017). J. Chem. Article ID 4238360, 6 pages.]).

In the title compound, Fig. 1[link], the central triazole ring is planar (r.m.s deviation = 0.0054 (13) Å) and makes dihedral angles of 56.15 (8) and 43.25 (9)° with the oxazol and benzene rings, respectively. The mean planes of the two eth­oxy­carbonyl groups make dihedral angles of 24.16 (11) and 51.90 (10)° with the triazole ring.

[Figure 1]
Figure 1
The structure of the title compound, showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 35% probability level. H atoms are represented as small spheres of arbitrary radii.

In the crystal, mol­ecules are linked by C—H⋯O and C—H⋯N hydrogen bonds into supra­molecular layers in the bc plane, Table 1[link] and Fig. 2[link].

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C7—H7B⋯N3i 0.97 2.59 3.454 (2) 149
C11—H11A⋯O1ii 0.96 2.56 3.392 (2) 145
Symmetry codes: (i) [x, -y+{\script{5\over 2}}, z-{\script{1\over 2}}]; (ii) [x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}].
[Figure 2]
Figure 2
A view of the mol­ecular packing along the c axis. Hydrogen bonds are drawn as dashed lines.

Synthesis and crystallization

A mixture of 4-(azido­meth­yl)-4-methyl-2-phenyl-4,5-di­hydro­oxazole (0.65 mmol) and diethyl acetyl­enedi­carboxyl­ate (0.65 mmol) was stirred for 12 h. The crude product was treated with ethyl acetate, the organic layer was washed with water, dried with Na2SO4, and the solvent removed. The product was purified by recrystallization from ether–hexane to afford the pure product. Suitable crystals of the title compound were obtained by recrystallization from its CHCl3 solution. The structure of the product was established on the basis of NMR spectroscopy (1H and 13C) and MS data.

Yield = 75% (white solid); m.p. = 92–94°C; Rf = 0.23 (ether/hexa­ne). 1H NMR (300.13 MHz; CDCl3): 1.30 (3H, CH3–CH2, t, J = 7.15 Hz); 1.38 (3H, CH3–CH2, t, J = 7.14 Hz); 1.41 (3H, CH3–Oxaz, s); 4.13–4.53 (2H, CH2–Oxaz, AB, J = 9.05 Hz); 4.24–4.38 (2H, –CH2–CH3, q, J = 7.15 Hz); 4.27–4.42 (2H, –CH2–CH3, q, J = 7.15 Hz); 4.76–4.93 (2H, --CH2–triazole, AB, J = 13.76 Hz); 7.35–7.84 (5Harom, m). 13C NMR (75.47 MHz; CDCl3): 13.66 (CH3–CH2); 14.14 (CH3–CH2); 25.22 (CH3–Oxaz); 56.38 (CH2–triazole); 61.71 (CH3CH2); 62.76 (CH3CH2); 70.77 (Cq–Oxaz); 75.13 (CH2–Oxaz); 127.00 (C-5, of triazole ring); 128.21; 128.46; 131.74 and 132.06 (6 Carom); 139.60 (C-4, of triazole ring); 158.73 and 159.93 (CO); 164.46 (CN). MS–EI: [M+1]+= 387.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link].

Table 2
Experimental details

Crystal data
Chemical formula C19H22N4O5
Mr 386.41
Crystal system, space group Monoclinic, P21/c
Temperature (K) 173
a, b, c (Å) 13.9450 (9), 16.3245 (10), 9.0473 (6)
β (°) 104.066 (2)
V3) 1997.8 (2)
Z 4
Radiation type Mo Kα
μ (mm−1) 0.10
Crystal size (mm) 0.34 × 0.21 × 0.17
 
Data collection
Diffractometer Bruker APEXII CCD
No. of measured, independent and observed [I > 2σ(I)] reflections 33174, 3529, 2938
Rint 0.032
(sin θ/λ)max−1) 0.595
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.037, 0.108, 1.07
No. of reflections 3529
No. of parameters 257
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.24, −0.26
Computer programs: APEX2 and SAINT (Bruker, 2009[Bruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXS2013 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), SHELXL2014 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]), 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.]).

Structural data


Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: publCIF (Westrip, 2010).

Diethyl 1-[(4-methyl-2-phenyl-4,5-dihydro-1,3-oxazol-4-yl)methyl]-1H-1,2,3-triazole-4,5-dicarboxylate top
Crystal data top
C19H22N4O5F(000) = 816
Mr = 386.41Dx = 1.285 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 298 reflections
a = 13.9450 (9) Åθ = 1.4–28.4°
b = 16.3245 (10) ŵ = 0.10 mm1
c = 9.0473 (6) ÅT = 173 K
β = 104.066 (2)°Prism, colourless
V = 1997.8 (2) Å30.34 × 0.21 × 0.17 mm
Z = 4
Data collection top
Bruker APEXII CCD
diffractometer
2938 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.032
Graphite monochromatorθmax = 25.0°, θmin = 2.5°
φ and ω scanh = 1616
33174 measured reflectionsk = 1919
3529 independent reflectionsl = 1010
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.037 w = 1/[σ2(Fo2) + (0.0558P)2 + 0.3505P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.108(Δ/σ)max = 0.001
S = 1.07Δρmax = 0.24 e Å3
3529 reflectionsΔρmin = 0.26 e Å3
257 parametersExtinction correction: SHELXL2014 (Sheldrick, 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.0066 (12)
Special details top

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
O10.91074 (9)0.92709 (7)0.10242 (14)0.0694 (4)
O20.75141 (8)0.95729 (7)0.11812 (12)0.0566 (3)
O30.78857 (14)1.13220 (8)0.14989 (14)0.0965 (5)
O40.76719 (8)1.21752 (6)0.03184 (11)0.0509 (3)
O50.75886 (7)0.88651 (7)0.37008 (12)0.0594 (3)
N10.92249 (8)0.98814 (7)0.22234 (13)0.0422 (3)
N20.93045 (9)1.05074 (7)0.32281 (14)0.0503 (3)
N30.88258 (9)1.11341 (7)0.25090 (13)0.0485 (3)
N40.82672 (9)0.82643 (7)0.19534 (14)0.0495 (3)
C10.86797 (9)1.01117 (8)0.08517 (15)0.0401 (3)
C20.84362 (10)1.09149 (8)0.10399 (15)0.0421 (3)
C30.84737 (11)0.95944 (9)0.05463 (16)0.0465 (3)
C40.72235 (16)0.91941 (14)0.2678 (2)0.0810 (6)
H4A0.72920.86040.25870.097*
H4B0.76420.93890.33170.097*
C50.61798 (18)0.94152 (15)0.3363 (2)0.0955 (7)
H5A0.57710.92190.27230.143*
H5B0.59710.91700.43530.143*
H5C0.61211.00000.34550.143*
C60.79680 (12)1.14840 (9)0.01821 (16)0.0506 (4)
C70.72300 (14)1.27614 (10)0.08724 (19)0.0635 (4)
H7A0.66181.25430.14970.076*
H7B0.76781.28650.15220.076*
C80.7035 (2)1.35238 (13)0.0141 (2)0.1027 (8)
H8A0.65701.34210.04630.154*
H8B0.67681.39240.09090.154*
H8C0.76411.37260.05000.154*
C90.97441 (10)0.91127 (9)0.27105 (18)0.0484 (4)
H9A1.03170.92280.35360.058*
H9B0.99810.88920.18690.058*
C100.91134 (10)0.84644 (8)0.32417 (17)0.0480 (4)
C110.97659 (14)0.77174 (10)0.3755 (2)0.0743 (5)
H11A0.93750.72840.40230.111*
H11B1.02860.78590.46250.111*
H11C1.00470.75390.29410.111*
C120.86204 (11)0.87770 (11)0.44759 (17)0.0558 (4)
H12A0.87020.83870.53060.067*
H12B0.89000.92990.48800.067*
C130.74973 (10)0.85130 (8)0.23094 (16)0.0448 (3)
C140.64819 (10)0.84697 (9)0.13450 (17)0.0477 (4)
C150.57447 (12)0.89708 (11)0.1616 (2)0.0630 (4)
H150.58830.93340.24330.076*
C160.48023 (13)0.89344 (14)0.0675 (2)0.0753 (5)
H160.43090.92750.08570.090*
C170.45948 (13)0.83999 (14)0.0518 (2)0.0778 (6)
H170.39610.83780.11520.093*
C180.53193 (14)0.78945 (14)0.0784 (2)0.0795 (6)
H180.51720.75260.15910.095*
C190.62626 (13)0.79287 (11)0.0134 (2)0.0630 (4)
H190.67530.75880.00610.076*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0646 (7)0.0756 (8)0.0763 (8)0.0012 (6)0.0331 (6)0.0257 (6)
O20.0532 (6)0.0723 (7)0.0424 (6)0.0056 (5)0.0080 (5)0.0191 (5)
O30.1746 (16)0.0726 (8)0.0387 (7)0.0207 (9)0.0192 (8)0.0032 (6)
O40.0572 (6)0.0520 (6)0.0406 (6)0.0088 (5)0.0060 (5)0.0069 (4)
O50.0456 (6)0.0838 (8)0.0460 (6)0.0019 (5)0.0058 (5)0.0103 (5)
N10.0384 (6)0.0426 (6)0.0439 (6)0.0020 (5)0.0067 (5)0.0030 (5)
N20.0558 (7)0.0458 (7)0.0431 (7)0.0008 (6)0.0001 (6)0.0041 (5)
N30.0561 (7)0.0454 (6)0.0396 (7)0.0007 (5)0.0031 (5)0.0038 (5)
N40.0424 (7)0.0503 (7)0.0520 (7)0.0029 (5)0.0040 (6)0.0057 (5)
C10.0364 (7)0.0449 (7)0.0399 (7)0.0048 (6)0.0110 (6)0.0033 (6)
C20.0433 (7)0.0457 (7)0.0370 (7)0.0035 (6)0.0093 (6)0.0027 (6)
C30.0515 (9)0.0460 (7)0.0458 (8)0.0048 (6)0.0189 (7)0.0065 (6)
C40.0879 (14)0.0981 (14)0.0515 (10)0.0074 (11)0.0062 (10)0.0337 (10)
C50.0958 (16)0.1154 (18)0.0590 (12)0.0133 (13)0.0128 (11)0.0138 (11)
C60.0610 (9)0.0516 (8)0.0389 (8)0.0037 (7)0.0114 (7)0.0004 (6)
C70.0762 (11)0.0596 (10)0.0493 (9)0.0064 (8)0.0048 (8)0.0160 (7)
C80.159 (2)0.0744 (13)0.0639 (12)0.0469 (14)0.0051 (14)0.0081 (10)
C90.0365 (7)0.0488 (8)0.0574 (9)0.0061 (6)0.0064 (6)0.0003 (7)
C100.0415 (8)0.0449 (7)0.0518 (9)0.0004 (6)0.0002 (6)0.0002 (6)
C110.0688 (11)0.0511 (9)0.0917 (14)0.0070 (8)0.0024 (10)0.0086 (9)
C120.0470 (8)0.0709 (10)0.0446 (8)0.0075 (7)0.0018 (7)0.0023 (7)
C130.0461 (8)0.0425 (7)0.0440 (8)0.0071 (6)0.0077 (6)0.0008 (6)
C140.0416 (8)0.0529 (8)0.0474 (8)0.0087 (6)0.0084 (6)0.0021 (7)
C150.0499 (9)0.0755 (11)0.0604 (10)0.0015 (8)0.0073 (8)0.0110 (8)
C160.0457 (9)0.1039 (14)0.0738 (12)0.0070 (9)0.0100 (9)0.0087 (11)
C170.0439 (9)0.1183 (16)0.0649 (12)0.0127 (10)0.0011 (8)0.0090 (11)
C180.0589 (11)0.1041 (15)0.0685 (12)0.0138 (10)0.0020 (9)0.0284 (11)
C190.0492 (9)0.0733 (11)0.0633 (10)0.0064 (8)0.0075 (8)0.0149 (8)
Geometric parameters (Å, º) top
O1—C31.1969 (17)C7—H7B0.9700
O2—C31.3222 (18)C8—H8A0.9600
O2—C41.4543 (19)C8—H8B0.9600
O3—C61.1983 (18)C8—H8C0.9600
O4—C61.3190 (18)C9—C101.526 (2)
O4—C71.4606 (18)C9—H9A0.9700
O5—C131.3614 (17)C9—H9B0.9700
O5—C121.4464 (18)C10—C111.525 (2)
N1—C11.3419 (17)C10—C121.534 (2)
N1—N21.3542 (16)C11—H11A0.9600
N1—C91.4622 (18)C11—H11B0.9600
N2—N31.3055 (16)C11—H11C0.9600
N3—C21.3561 (17)C12—H12A0.9700
N4—C131.2607 (18)C12—H12B0.9700
N4—C101.4795 (19)C13—C141.473 (2)
C1—C21.3753 (19)C14—C151.382 (2)
C1—C31.4896 (19)C14—C191.383 (2)
C2—C61.470 (2)C15—C161.383 (2)
C4—C51.481 (3)C15—H150.9300
C4—H4A0.9700C16—C171.364 (3)
C4—H4B0.9700C16—H160.9300
C5—H5A0.9600C17—C181.370 (3)
C5—H5B0.9600C17—H170.9300
C5—H5C0.9600C18—C191.376 (3)
C7—C81.465 (3)C18—H180.9300
C7—H7A0.9700C19—H190.9300
C3—O2—C4116.06 (12)N1—C9—C10114.14 (11)
C6—O4—C7114.73 (12)N1—C9—H9A108.7
C13—O5—C12105.35 (11)C10—C9—H9A108.7
C1—N1—N2110.18 (11)N1—C9—H9B108.7
C1—N1—C9130.31 (12)C10—C9—H9B108.7
N2—N1—C9119.44 (11)H9A—C9—H9B107.6
N3—N2—N1107.95 (11)N4—C10—C11111.47 (12)
N2—N3—C2108.44 (11)N4—C10—C9108.38 (12)
C13—N4—C10107.05 (12)C11—C10—C9107.67 (13)
N1—C1—C2104.72 (11)N4—C10—C12103.54 (11)
N1—C1—C3125.13 (12)C11—C10—C12112.58 (14)
C2—C1—C3130.02 (13)C9—C10—C12113.14 (12)
N3—C2—C1108.70 (12)C10—C11—H11A109.5
N3—C2—C6124.71 (12)C10—C11—H11B109.5
C1—C2—C6125.97 (12)H11A—C11—H11B109.5
O1—C3—O2126.13 (14)C10—C11—H11C109.5
O1—C3—C1123.36 (14)H11A—C11—H11C109.5
O2—C3—C1110.48 (11)H11B—C11—H11C109.5
O2—C4—C5107.98 (16)O5—C12—C10104.43 (11)
O2—C4—H4A110.1O5—C12—H12A110.9
C5—C4—H4A110.1C10—C12—H12A110.9
O2—C4—H4B110.1O5—C12—H12B110.9
C5—C4—H4B110.1C10—C12—H12B110.9
H4A—C4—H4B108.4H12A—C12—H12B108.9
C4—C5—H5A109.5N4—C13—O5118.56 (13)
C4—C5—H5B109.5N4—C13—C14126.07 (13)
H5A—C5—H5B109.5O5—C13—C14115.36 (12)
C4—C5—H5C109.5C15—C14—C19119.22 (15)
H5A—C5—H5C109.5C15—C14—C13121.06 (14)
H5B—C5—H5C109.5C19—C14—C13119.71 (14)
O3—C6—O4124.59 (14)C14—C15—C16120.15 (16)
O3—C6—C2121.74 (14)C14—C15—H15119.9
O4—C6—C2113.66 (12)C16—C15—H15119.9
O4—C7—C8108.35 (14)C17—C16—C15120.13 (18)
O4—C7—H7A110.0C17—C16—H16119.9
C8—C7—H7A110.0C15—C16—H16119.9
O4—C7—H7B110.0C16—C17—C18120.06 (17)
C8—C7—H7B110.0C16—C17—H17120.0
H7A—C7—H7B108.4C18—C17—H17120.0
C7—C8—H8A109.5C17—C18—C19120.48 (18)
C7—C8—H8B109.5C17—C18—H18119.8
H8A—C8—H8B109.5C19—C18—H18119.8
C7—C8—H8C109.5C18—C19—C14119.95 (17)
H8A—C8—H8C109.5C18—C19—H19120.0
H8B—C8—H8C109.5C14—C19—H19120.0
C1—N1—N2—N30.62 (15)N2—N1—C9—C1095.08 (15)
C9—N1—N2—N3176.55 (11)C13—N4—C10—C11128.55 (15)
N1—N2—N3—C20.01 (15)C13—N4—C10—C9113.13 (13)
N2—N1—C1—C20.96 (14)C13—N4—C10—C127.27 (15)
C9—N1—C1—C2175.80 (12)N1—C9—C10—N461.10 (16)
N2—N1—C1—C3177.17 (12)N1—C9—C10—C11178.19 (13)
C9—N1—C1—C30.4 (2)N1—C9—C10—C1253.13 (16)
N2—N3—C2—C10.61 (16)C13—O5—C12—C109.24 (15)
N2—N3—C2—C6170.79 (13)N4—C10—C12—O510.01 (15)
N1—C1—C2—N30.96 (15)C11—C10—C12—O5130.54 (13)
C3—C1—C2—N3176.90 (13)C9—C10—C12—O5107.10 (13)
N1—C1—C2—C6170.31 (13)C10—N4—C13—O51.56 (17)
C3—C1—C2—C65.6 (2)C10—N4—C13—C14177.70 (13)
C4—O2—C3—O17.0 (2)C12—O5—C13—N45.31 (17)
C4—O2—C3—C1170.88 (14)C12—O5—C13—C14175.35 (12)
N1—C1—C3—O153.3 (2)N4—C13—C14—C15159.58 (16)
C2—C1—C3—O1121.89 (18)O5—C13—C14—C1519.7 (2)
N1—C1—C3—O2128.71 (14)N4—C13—C14—C1919.4 (2)
C2—C1—C3—O256.09 (19)O5—C13—C14—C19161.28 (14)
C3—O2—C4—C5165.55 (16)C19—C14—C15—C160.6 (3)
C7—O4—C6—O30.8 (2)C13—C14—C15—C16178.45 (16)
C7—O4—C6—C2178.29 (13)C14—C15—C16—C170.4 (3)
N3—C2—C6—O3158.83 (17)C15—C16—C17—C180.3 (3)
C1—C2—C6—O311.1 (2)C16—C17—C18—C190.9 (3)
N3—C2—C6—O420.2 (2)C17—C18—C19—C140.7 (3)
C1—C2—C6—O4169.83 (13)C15—C14—C19—C180.0 (3)
C6—O4—C7—C8174.17 (17)C13—C14—C19—C18179.03 (17)
C1—N1—C9—C1088.40 (17)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C7—H7B···N3i0.972.593.454 (2)149
C11—H11A···O1ii0.962.563.392 (2)145
Symmetry codes: (i) x, y+5/2, z1/2; (ii) x, y+3/2, z+1/2.
 

References

First citationBoukhssas, S., Aouine, Y., Faraj, H., Alami, A., El Hallaoui, A. & Bekkari, H. (2017). J. Chem. Article ID 4238360, 6 pages.  Google Scholar
First citationBruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationKiss, L., Forró, E., Sillanpää, R. & Fülöp, F. (2010). Tetrahedron, 66, 3599–3607.  CrossRef CAS Google Scholar
First citationLutz, J. F. (2008). Angew. Chem. Int. Ed. 47, 2182–2184.  CrossRef CAS Google Scholar
First citationOliva, A. I., Christmann, U., Font, D., Cuevas, F., Ballester, P., Buschmann, H., Torrens, A., Yenes, S. & Pericàs, M. A. (2008). Org. Lett. 10, 1617–1619.  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 citationSheldrick, G. M. (2015). Acta Cryst. C71, 3–8.  Web of Science CrossRef 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

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 logoIUCrDATA
ISSN: 2414-3146
Follow IUCr Journals
Sign up for e-alerts
Follow IUCr on Twitter
Follow us on facebook
Sign up for RSS feeds

[# https x2 cm 20170801 %]