Issue contents cross.png
Download PDF of article cross.png
Download CIF cross.png
3D view cross.png
Navigation cross.png
Highlighting cross.png
Dictionary of Crystallography reference
IUPAC Gold Book reference
more ...
Download citation cross.png
FormatBIBTeX
EndNote
RefMan
Refer
Medline
CIF
SGML
Plain Text
Text
cross.png
share
Previous article cross.png
Next article cross.png
Previous article cross.png
Issue contents cross.png
Download PDF of article cross.png
Download CIF cross.png
3D view cross.png
Navigation cross.png
Highlighting cross.png
Dictionary of Crystallography reference
IUPAC Gold Book reference
more ...
Download citation cross.png
FormatBIBTeX
EndNote
RefMan
Refer
Medline
CIF
SGML
Plain Text
Text
cross.png
share
Next article cross.png

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

Journal logoSTRUCTURAL
CHEMISTRY
ISSN: 2053-2296
Volume 63| Part 4| April 2007| Pages o239-o242
https://doi.org/10.1107/S0108270107008712

Carbon­yl–carbonyl, carbon­yl–π and carbon­yl–halogen dipolar inter­actions as the directing motifs of the supra­molecular structure of ethyl 6-chloro-2-oxo-2H-chromene-3-carboxyl­ate and ethyl 6-bromo-2-oxo-2H-chromene-3-carboxyl­ate

CROSSMARK_Color_square_no_text.svg
Rocio J. Santos-Contreras,a Francisco J. Martínez-Martínez,a Efrén V. García-Báez,b Itzia I. Padilla-Martínez,b* Ana L. Perazaa and Herbert Höpflc

aFacultad de Ciencias Químicas, Universidad de Colima, Carretera Coquimatlán, Colima 28400, Mexico, bUnidad Profesional Interdisciplinaria de Biotecnología, Instituto Politécnico Nacional, Avenida Acueducto s/n, Barrio La Laguna Ticomán, DF 07340, Mexico, and cCentro de Investigaciónes Químicas, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001. Col. Chamilpa., Cuernavaca, Morelos, CP 62210, Mexico
*Correspondence e-mail: ipadilla@acei.upibi.ipn.mx

(Received 9 January 2007; accepted 21 February 2007; online 17 March 2007)

The title compounds, C12H9ClO4, (I), and C12H9BrO4, (II), are isomorphous and crystallize in the monoclinic space group P21/c. Both compounds present an anti conformation between the 3-carb­oxy and the lactone carbonyl groups. Both carbonyl groups are out of the plane defined by the remaining chromene atoms, by 8.37 (6) and 17.57 (6)° for (I), and by 9.07 (8) and 18.96 (18)° for (II), owing to their involvement in inter­molecular inter­actions. In both compounds, layers of centrosymmetric hydrogen-bonded dimers are developed in the [[\overline{5}] [\overline{2}] 22] plane through C—H⋯O inter­actions, involving both carbonyl groups as acceptors. Two families of dimers stack through C=O⋯C=O, C=O⋯π and C—X⋯C=O (X = Cl and Br) dipolar inter­actions, as well as a C—H⋯π inter­action, developing the three-dimensional structure along the c axis.

Comment

Coumarins have demonstrated a great variety of biological properties as anti-inflamatories (Kontogiorgis & Hadjipavlou-Litina, 2005[Kontogiorgis, C. A. & Hadjipavlou-Litina, D. J. (2005). J. Med. Chem. 48, 6400-6408.]), anti­bacterials (Gursoy & Karali, 2003[Gursoy, A. & Karali, N. (2003). Turk. J. Chem. 27, 545-551.]) and anti­helmintics (de Marchi et al., 2004[Marchi, A. A. de, Castilho, M. S., Nascimento, P. G. B., Archanjo, F. C., Del Ponte, G., Oliva, G. & Pupo, M. T. (2004). Bioorg. Med. Chem. 12, 4823-4833.]). They have been proposed in HIV (Lee & Morris, 1999[Lee, K. H. & Morris, S. (1999). Pure Appl. Chem. 71, 1045-1051.]) and cancer (Lacy & O'Kennedy, 2004[Lacy, A. & O'Kennedy, R. (2004). Curr. Pharm. Des. 10, 3797-3811.]) treatment, as well as being inhibitors of monoamino­oxidase (Chimenti et al., 2004[Chimenti, F., Secci, D., Bolasco, A., Chimenti, P., Granese, A., Befani, O., Turín, P. & Ortuso, F. (2004). Bioorg. Med. Chem. Lett. 14, 3697-3703.]; Santana et al., 2006[Santana, L., Uriarte, E., Gonzalez, H., Zagotto, G., Soto, R. & Mendez, E. (2006). J. Med. Chem. 49, 1149-1156.]). Non-covalent inter­actions are involved in most of the mol­ecular recognition processes. Particularly, hydrogen bonding and π-stacking inter­actions are responsible for the self-association of coumarin derivatives in the solid state (Magaña-Vergara et al., 2004[Magaña-Vergara, N. E., Martínez-Martínez, F. J., Padilla-Martínez, I. I., Höpfl, H. & García-Báez, E. V. (2004). Acta Cryst. E60, o2306-o2308.]; García-Báez et al., 2003[García-Báez, E. V., Martínez-Martínez, F. J., Höpfl, H. & Padilla-Martínez, I. I. (2003). Cryst. Growth Des. 3, 35-45.]). Following on from these studies, we report here the mol­ecular and supra­molecular structures of the isostructural ethyl 6-­chloro- and 6-bromo-2-oxo-1H-benzopyran-3-carboxyl­ates, viz. (I)[link] and (II)[link], respectively.

[Scheme 1]

The title compounds are isomorphous; they crystallize in the monoclinic space group P21/c with four mol­ecules in the unit cell. The mol­ecular structures of (I)[link] and (II)[link] are shown in Figs. 1[link] and 2[link], and selected bond lengths and angles are listed in Tables 1[link] and 3[link], respectively. The geometric parameters of the coumarin ring are comparable to those reported for similar structures retrieved from the Cambridge Structural Database (Version of May 2005; Allen, 2002[Allen, F. H. (2002). Acta Cryst. B58, 380-388.]). Most of the bond distances and angles in (I)[link] and (II)[link] are very similar to the values reported for the isomorphic ethyl coumarin-3-carboxyl­ate, (III) (García-Báez et al., 2003[García-Báez, E. V., Martínez-Martínez, F. J., Höpfl, H. & Padilla-Martínez, I. I. (2003). Cryst. Growth Des. 3, 35-45.]), except for the O1—C9 bond length, which is slightly shorter; the mean value is 1.366 (2) Å for (I)[link] and (II)[link], compared with 1.377 (2) Å in (III). This is probably due to the inductive negative effect of the halogen atom on the lactone O atom (O1) lone pair of electrons. Compounds (I)[link] and (II)[link] present an anti conformation between the 3-carb­oxy and the lactone carbonyl groups, in contrast to the previously reported syn arrangement in (III). In both title mol­ecules, the lactone and the carboxyl­ate carbonyl groups are out of the plane defined by atoms O1/C3–C10 by 8.37 (6) and 17.57 (6)°, respectively, for (I)[link], and by 9.07 (8) and 18.96 (18)°, respectively, for (II)[link]. The above-mentioned carbonyl deviations from planarity seem to be related to inter­molecular inter­actions. It is inter­esting to note that the replacement of Cl by Br does not alter the mol­ecular packing.

In the crystal structures of compounds (I)[link] and (II)[link], hydrogen-bonded dimers are formed by self-complementary inter­actions involving the carboxyl­ate carbonyl O atom as a hydrogen-bond acceptor, and the C4—H4 and C5—H5 groups as hydrogen-bond donors (Tables 2[link] and 4[link]), so defining an R22(14)[R21(6)] motif (Bernstein et al., 1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]). This dimer, which lies in the family of planes [[\overline{3}] 3 14], is hydrogen bonded to another dimer lying in the family of planes [[\overline{3}] [\overline{3}] 14], through two C—H⋯O inter­actions (C7⋯O2ii and C8⋯O2ii; the symmetry code is as in Tables 2[link] and 4[link]), to form an R21(5) motif. The hydrogen-bonding motifs are shown in Fig. 3[link] for compound (I)[link]. Thus, layers of centrosymmetric hydrogen-bonded dimers are developed in the [[\overline{5}] [\overline{2}] 22] plane.

In both compounds, the two families of dimers stack through C=O⋯C=O, C=O⋯π and C—Cl⋯C=O dipolar inter­actions to develop the third dimension (Fig. 4[link]). In the absence of strong hydrogen-bonding donors, carbonyl dipolar inter­actions are strong enough to direct the crystal packing of both isomorphs. Two self-complementary sheared parallel C=O⋯C=O inter­actions (Allen et al., 1998[Allen, F. H., Baalham, C. A., Lommerse, J. P. M. & Raithby, P. R. (1998). Acta Cryst. B54, 320-329.]) form a stacked centrosymmetric dimer [O11⋯C2iii = 3.130 (2) Å, C11=O11⋯C2iii = 108.9 (1)° and C11⋯O2=C2 = 55.1 (1)° for (I)[link]; O11⋯C2iii = 3.130 (3) Å, C11=O11⋯C2iii = 109.0 (2)° and C11⋯O2=C2 = 55.5 (2)° for (II)[link]; symmetry code: (iii) −x + 1, −y, −z + 1]. In this inter­action, the 3-carb­oxy carbonyl group acts as the donor and the lactone carbonyl group as the acceptor of electronic density. The former carbonyl group and the lactone ring (centroid Cg1) are almost parallel [C11=O11⋯Cg1iii = 96.5 (1) and 96.8 (2)° for (I)[link] and (II)[link], respectively], and are separated by 3.034 (3) Å in (I)[link] and 3.035 (2) Å in (II)[link]. This gives rise to the inter­action of the lone pair of atom O11 with the electron-deficient lactone ring (García-Báez et al., 2003[García-Báez, E. V., Martínez-Martínez, F. J., Höpfl, H. & Padilla-Martínez, I. I. (2003). Cryst. Growth Des. 3, 35-45.]). This type of inter­action has also been observed for 4-chloro-3-nitro­coumarin (Fujii et al., 2005[Fujii, I., Mano, Y. & Hirayama, N. (2005). Acta Cryst. E61, o1456-o1458.]).

A weak Csp3—H⋯π inter­action (Umezawa et al., 1998[Umezawa, Y., Tsuboyama, S., Honda, K., Uzawa, J. & Nishio, M. (1998). Bull. Chem. Soc. Jpn, 71, 1207-1213.]) complements the packing [C13⋯Cg2iii = 3.787 (2) Å for (I)[link] and 3.833 (3) Å for (II)[link], and C13—H13A⋯Cg2iii = 150.8 (2)° for (I)[link] and 150.3 (3)° for (II)[link]; Cg2 is the centroid of the benzene ring]. This set of stacked dimers lying in the family of planes [[\overline{3}] 3 14] is linked to the set of stacked dimers lying in the family of planes [[\overline{3}] [\overline{3}] 14] through dipolar C—Cl(δ−)⋯C(δ+)=O inter­actions [Cl1⋯C2iv = 3.456 (2) Å and C11—Cl1⋯C2iv = 95.8 (1)° for (I)[link]; Br1⋯C2iv = 3.516 (3) Å and C11—Br1⋯C2iv = 95.5 (2)° for (II)[link]; symmetry code: (iv) −x + 1, y + [{1\over 2}], −z + [{1\over 2}]]. This inter­action shows distances below the sum of the van der Waals radii of the halogen and C atoms (C = 1.70 Å, Cl = 1.80 Å and Br = 1.90 Å; Bondi, 1964[Bondi, A. J. (1964). Chem. Phys. 68, 441.]), with an almost perpendicular arrangement between the donor and the acceptor groups, in agreement with the side-on geometry proposed for C—X⋯E inter­actions (X = halogen and E = electrophile; Lommerse et al., 1996[Lommerse, J. P. M., Stone, A. J., Taylor, R. & Allen, F. H. (1996). J. Am. Chem. Soc. 118, 3108-3116.]; Bosch & Barnes, 2002[Bosch, E. & Barnes, C. L. (2002). Cryst. Growth Des. 2, 299-302.]) and in contrast to the head-on geometry proposed for C—X⋯Nu (X = halogen and Nu = nucleophile) inter­actions (Ouvrard et al., 2003[Ouvrard, C., Le Questel, J.-Y., Berthelot, M. & Laurence, C. (2003). Acta Cryst. B59, 512-526.]; Auffinger et al., 2004[Auffinger, P., Hays, F. A., Westhof, E. & Ho, P. S. (2004). PNAS, 101, 16789-16794.]).

As a consequence of the above-mentioned group of inter­actions, a block of zigzag centrosymmetric pairs of dimers stacking along the c-axis direction is formed. The C3⋯C4iii distances of 3.602 (3) and 3.592 (4) Å for (I)[link] and (II)[link], respectively, are in the expected range for photochemical dimerization (Gnanaguru et al., 1985[Gnanaguru, K., Ramasubbu, N., Venkatesan, K. & Ramamurthy, V. (1985). J. Org. Chem. 50, 2337-2346.]). Thus, further studies on the photoreactivity of compounds (I)[link] and (II)[link] are currently being carried out.

[Figure 1]
Figure 1
The mol­ecular structure of (I)[link], showing the atomic numbering scheme and displacement ellipsoids drawn at the 30% probability level.
[Figure 2]
Figure 2
The mol­ecular structure of (II)[link], showing the atomic numbering scheme and displacement ellipsoids drawn at the 30% probability level.
[Figure 3]
Figure 3
Layers of centrosymmetric hydrogen-bonded dimers of (I)[link], viewed in the ab plane. R22(14)[R21(6)] and R21(5) motifs are shown. Some H atoms have been omitted for clarity. [Symmetry codes: (i) −x + 2, −y, −z + 1; (ii) −x, y + [{1\over 2}], −z + [{1\over 2}].]
[Figure 4]
Figure 4
The stacking arrangement of (I)[link], in centrosymmetric pairs, viewed along the c axis. C11=O11⋯C2=O2, C11=O11⋯Cg1 and C6—X⋯C2=O2 (X = Cl and Br) dipolar inter­actions, as well as C13—H13A⋯Cg2 inter­actions, combine to develop the third dimension along the c axis. [Symmetry codes: (iii) −x + 1, −y, −z + 1; (iv) −x + 1, y + [{1\over 2}], −z + [{1\over 2}].]

Experimental

Compounds (I)[link] and (II)[link] were synthesized as reported by Bonsignore et al. (1995[Bonsignore, L., Cottiglia, F., Maccioni, A. & Secci, D. (1995). J. Heterocycl. Chem. 32, 573-577.]), starting from 5-chloro- or 5-bromosalicylaldehyde with diethyl malonate in equimolar amounts. All reagents were purchased from Aldrich. Crystals suitable for X-ray analysis were obtained by recrystallization from ethanol. For compound (I)[link] (m.p. 440 K), FT–IR (ν, cm−1): 1743, 1700 (C=O); 1H NMR (DMSO-d6): δ 8.72 (s, 1H, H-­4), 8.06 (d, 1H, H-5), 7.78 (dd, 1H, H-7), 7.48 (d, 1H, H-8), 4.3 (q, 2H, OCH2), 1.31 (t, 3H, CH3); 13C NMR (DMSO-d6): δ 155.4 (C2), 118.6 (C3), 147.3 (C4), 129.0 (C5), 128.3 (C6), 133.7 (C7), 118.2 (C8), 153.3 (C9), 119.1 (C10), 162.2 (C11), 61.3 (C13), 13.9 (C14). For compound (II)[link] (m.p. 445 K), FT–IR (ν, cm−1): 1743, 1718 (C=O); 1H NMR (CDCl3): δ 8.42 (s, 1H, H-4), 7.69 (d, 1H, H-5), 7.73 (dd, 1H, H-7), 7.23 (d, 1H, H-8), 4.4 (q, 2H, OCH2), 1.39 (t, 3H, CH3); 13C NMR (CDCl3): δ 155.9 (C2), 117.3 (C3), 147.0 (C4), 131.4 (C5), 119.3 (C6), 136.8 (C7), 118.4 (C8), 153.8 (C9), 119.2 (C10), 162.5 (C11), 62.1 (C13), 14.0 (C14).

Compound (I)[link]

Crystal data

  • C12H9ClO4

  • Mr = 252.64

  • Monoclinic, P 21 /c

  • a = 5.7982 (5) Å

  • b = 13.0702 (12) Å

  • c = 15.5540 (12) Å

  • β = 108.191 (3)°

  • V = 1119.83 (17) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.34 mm−1

  • T = 293 (2) K

  • 0.20 × 0.18 × 0.14 mm
Data collection

  • Bruker SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.935, Tmax = 0.954

  • 8206 measured reflections

  • 2615 independent reflections

  • 2310 reflections with I > 2σ(I)

  • Rint = 0.024
Refinement

  • R[F2 > 2σ(F2)] = 0.055

  • wR(F2) = 0.155

  • S = 1.08

  • 2615 reflections

  • 155 parameters

  • H-atom parameters constrained

  • Δρmax = 0.34 e Å−3

  • Δρmin = −0.32 e Å−3

Table 1
Selected geometric parameters (Å, °) for (I)[link]

Cl1—C6 1.736 (2) 
O1—C2 1.382 (2)
O1—C9 1.366 (2)
O2—C2 1.188 (2)
O11—C11 1.200 (3)
C2—C3 1.470 (3)
C3—C4 1.342 (3)
C2—O1—C9 122.98 (15)
O1—C2—C3 115.78 (15)
C3—C4—C10 121.38 (17)
Cl1—C6—C5 119.20 (17)
O11—C11—O12 124.10 (18)
O11—C11—C3 121.72 (17)
O12—C11—C3 114.18 (16)
O2—C2—C3—C11 5.4 (3)
C2—C3—C11—O11 −156.44 (19)

Table 2
Hydrogen-bond geometry (Å, °) for (I)[link]

D—H⋯A D—H H⋯A D⋯A D—H⋯A
C4—H4⋯O11i 0.93 2.54 3.346 (3) 145
C5—H5⋯O11i 0.93 2.43 3.263 (3) 149
C7—H7⋯O2ii 0.93 2.59 3.182 (3) 122
C8—H8⋯O2ii 0.93 2.59 3.182 (3) 122
Symmetry codes: (i) -x+2, -y, -z+1; (ii) [-x, y+{\script{1\over 2}}, -z+{\script{1\over 2}}].

Compound (II)[link]

Crystal data

  • C12H9BrO4

  • Mr = 297.10

  • Monoclinic, P 21 /c

  • a = 5.8432 (6) Å

  • b = 13.2073 (14) Å

  • c = 15.6959 (15) Å

  • β = 109.327 (3)°

  • V = 1143.0 (2) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 3.60 mm−1

  • T = 293 (2) K

  • 0.26 × 0.15 × 0.12 mm
Data collection

  • Bruker SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.455, Tmax = 0.672

  • 12998 measured reflections

  • 2754 independent reflections

  • 2091 reflections with I > 2σ(I)

  • Rint = 0.041
Refinement

  • R[F2 > 2σ(F2)] = 0.045

  • wR(F2) = 0.123

  • S = 1.05

  • 2754 reflections

  • 155 parameters

  • H-atom parameters constrained

  • Δρmax = 1.00 e Å−3

  • Δρmin = −0.26 e Å−3

Table 3
Selected geometric parameters (Å, °) for (II)[link]

Br1—C6 1.888 (3)
O1—C2 1.379 (3)
O1—C9 1.366 (3)
O2—C2 1.189 (4)
O11—C11 1.198 (4)
C3—C4 1.341 (4)
C2—O1—C9 123.1 (2)
O1—C2—C3 115.6 (2)
C3—C4—C10 121.3 (3)
Br1—C6—C5 119.0 (2)
O11—C11—O12 124.4 (3)
O12—C11—C3 114.1 (2)
O2—C2—C3—C11 6.1 (5)
C2—C3—C11—O11 −155.0 (3)

Table 4
Hydrogen-bond geometry (Å, °) for (II)[link]

D—H⋯A D—H H⋯A D⋯A D—H⋯A
C4—H4⋯O11i 0.93 2.60 3.394 (3) 143
C5—H5⋯O11i 0.93 2.42 3.264 (4) 151
C7—H7⋯O2ii 0.93 2.55 3.171 (4) 125
C8—H8⋯O2ii 0.93 2.69 3.239 (3) 119
Symmetry codes: (i) -x+2, -y, -z+1; (ii) [-x, y+{\script{1\over 2}}, -z+{\script{1\over 2}}].

H atoms were included in calculated positions and refined as riding atoms. The C—H distances are in the range 0.93–0.97 Å and Uiso(H) values were set at 1.5 or 1.2 times Ueq(parent C atom).

For both compounds, data collection: SMART (Bruker, 2002[Bruker (2002). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2002[Bruker (2002). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); molecular graphics: MERCURY (Version 1.4; Bruno et al., 2002[Bruno, I. J., Cole, J. C., Edgington, P. R., Kessler, M., Macrae, C. F., McCabe, P., Pearson, J. & Taylor, R. (2002). Acta Cryst. B58, 389-397.]); software used to prepare material for publication: SHELXL97 and WinGX2003 (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]).

Supporting information

Crystal structure: contains datablocks I, II, global. DOI: https://doi.org/10.1107/S0108270107008712/su3001sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S0108270107008712/su3001Isup2.hkl

Structure factors: contains datablock II. DOI: https://doi.org/10.1107/S0108270107008712/su3001IIsup3.hkl


Computing details top

For both compounds, data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Mercury (Version 1.4; Bruno et al., 2002); software used to prepare material for publication: SHELXL97 and WinGX2003 (Farrugia, 1999).

(I) ethyl 6-chloro-2-oxo-2H-chromene-3-carboxylate top
Crystal data top
C12H9ClO4F(000) = 520
Mr = 252.64Dx = 1.499 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 600 reflections
a = 5.7982 (5) Åθ = 20–25°
b = 13.0702 (12) ŵ = 0.34 mm−1
c = 15.5540 (12) ÅT = 293 K
β = 108.191 (3)°Block, colorless
V = 1119.83 (17) Å30.20 × 0.18 × 0.14 mm
Z = 4
Data collection top
Bruker SMART CCD area-detector
diffractometer		2310 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.024
φ and ω scansθmax = 28.3°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		h = −5→7
Tmin = 0.935, Tmax = 0.954k = −17→17
8206 measured reflectionsl = −19→20
2615 independent reflections
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)] = 0.055Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.155H-atom parameters constrained
S = 1.08 w = 1/[σ2(Fo2) + (0.0847P)2 + 0.376P]
where P = (Fo2 + 2Fc2)/3
2615 reflections(Δ/σ)max < 0.001
155 parametersΔρmax = 0.34 e Å−3
0 restraintsΔρmin = −0.32 e Å−3
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
Cl10.83937 (11)0.44331 (4)0.37740 (5)0.0658 (2)
O10.1703 (2)0.09721 (10)0.31028 (10)0.0463 (4)
O20.0698 (3)−0.05735 (11)0.33959 (12)0.0576 (5)
O110.7769 (3)−0.13011 (11)0.48547 (11)0.0560 (5)
O120.4434 (3)−0.19667 (10)0.38878 (11)0.0531 (5)
C20.2323 (3)0.00067 (14)0.34636 (13)0.0407 (5)
C30.4928 (3)−0.01738 (14)0.39037 (12)0.0373 (5)
C40.6526 (3)0.05987 (13)0.40360 (13)0.0389 (5)
C50.7355 (3)0.24450 (15)0.38742 (14)0.0437 (6)
C60.6460 (4)0.33847 (15)0.35488 (14)0.0446 (6)
C70.4034 (4)0.35195 (15)0.30462 (14)0.0476 (6)
C80.2464 (4)0.27051 (16)0.28880 (14)0.0477 (6)
C90.3332 (3)0.17570 (14)0.32359 (12)0.0395 (5)
C100.5774 (3)0.16098 (14)0.37194 (12)0.0383 (5)
C110.5865 (3)−0.12015 (14)0.42679 (13)0.0398 (5)
C130.5294 (4)−0.29786 (16)0.42282 (18)0.0587 (7)
C140.3247 (6)−0.3694 (2)0.3897 (2)0.0822 (10)
H40.815700.047370.433980.0466*
H50.899230.236310.419380.0525*
H70.347620.416210.281720.0572*
H80.084010.278950.255180.0573*
H13A0.58670−0.297510.488460.0705*
H13B0.66243−0.318380.401270.0705*
H14A0.27332−0.370990.324790.1233*
H14B0.19238−0.347200.409910.1233*
H14C0.37491−0.436630.412910.1233*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0589 (4)0.0426 (3)0.0925 (5)−0.0088 (2)0.0189 (3)0.0069 (3)
O10.0318 (7)0.0395 (7)0.0544 (8)0.0035 (5)−0.0054 (6)−0.0015 (6)
O20.0374 (8)0.0467 (9)0.0773 (11)−0.0043 (6)0.0014 (7)−0.0066 (7)
O110.0412 (8)0.0437 (8)0.0684 (10)0.0043 (6)−0.0041 (7)0.0112 (7)
O120.0501 (8)0.0338 (7)0.0632 (9)0.0023 (6)0.0001 (7)0.0012 (6)
C20.0326 (9)0.0363 (9)0.0455 (10)0.0008 (7)0.0009 (7)−0.0060 (7)
C30.0331 (9)0.0355 (9)0.0392 (9)0.0042 (7)0.0054 (7)0.0005 (7)
C40.0286 (8)0.0383 (9)0.0449 (10)0.0053 (7)0.0045 (7)0.0034 (7)
C50.0329 (9)0.0408 (10)0.0544 (11)0.0012 (7)0.0092 (8)0.0033 (8)
C60.0435 (10)0.0370 (9)0.0527 (11)−0.0013 (8)0.0141 (9)0.0012 (8)
C70.0496 (11)0.0380 (10)0.0511 (11)0.0101 (8)0.0097 (9)0.0085 (8)
C80.0400 (10)0.0452 (10)0.0487 (10)0.0108 (8)0.0006 (8)0.0038 (8)
C90.0343 (9)0.0389 (9)0.0399 (9)0.0033 (7)0.0039 (7)−0.0021 (7)
C100.0319 (9)0.0363 (9)0.0432 (9)0.0052 (7)0.0066 (7)0.0021 (7)
C110.0362 (9)0.0372 (9)0.0441 (10)0.0019 (7)0.0099 (8)0.0016 (7)
C130.0564 (13)0.0352 (10)0.0757 (15)0.0058 (9)0.0078 (11)0.0050 (10)
C140.0813 (19)0.0428 (13)0.104 (2)−0.0090 (12)0.0024 (16)0.0001 (13)
Geometric parameters (Å, º) top
Cl1—C61.736 (2)C7—C81.372 (3)
O1—C21.382 (2)C8—C91.383 (3)
O1—C91.366 (2)C9—C101.394 (3)
O2—C21.188 (2)C13—C141.472 (4)
O11—C111.200 (3)C4—H40.9300
O12—C111.316 (2)C5—H50.9300
O12—C131.454 (3)C7—H70.9300
C2—C31.470 (3)C8—H80.9300
C3—C41.342 (3)C13—H13A0.9700
C3—C111.493 (3)C13—H13B0.9700
C4—C101.430 (3)C14—H14A0.9600
C5—C61.368 (3)C14—H14B0.9600
C5—C101.397 (3)C14—H14C0.9600
C6—C71.391 (3)
Cl1···C2i3.456 (2)C3···C11ii3.514 (3)
O1···O11ii3.125 (2)C4···O2viii3.270 (3)
O2···C4iii3.270 (3)C4···O11v3.346 (3)
O2···O122.749 (2)C4···C11ii3.433 (3)
O2···C8iv3.182 (3)C5···O11v3.263 (3)
O2···C7iv3.182 (3)C7···O2vi3.182 (3)
O11···C4v3.346 (3)C8···O2vi3.182 (3)
O11···C5v3.263 (3)C9···O11ii3.281 (2)
O11···C2ii3.130 (2)C10···C11ii3.584 (3)
O11···C9ii3.281 (2)C11···C3ii3.514 (3)
O11···O1ii3.125 (2)C11···C4ii3.433 (3)
O12···O22.749 (2)C11···C10ii3.584 (3)
O1···H14Avi2.8000H4···O2viii2.7500
O2···H7iv2.5900H4···O112.4900
O2···H4iii2.7500H4···H52.5400
O2···H8iv2.5900H4···O11v2.5400
O11···H13B2.7700H5···H42.5400
O11···H13A2.4600H5···O11v2.4300
O11···H4v2.5400H7···O2vi2.5900
O11···H5v2.4300H8···O2vi2.5900
O11···H42.4900H13A···O112.4600
C2···Cl1vii3.456 (2)H13B···O112.7700
C2···O11ii3.130 (2)H14A···O1iv2.8000
C3···C3ii3.416 (3)
C2—O1—C9122.98 (15)O11—C11—C3121.72 (17)
C11—O12—C13115.55 (18)O12—C11—C3114.18 (16)
O1—C2—O2116.62 (17)O12—C13—C14107.6 (2)
O1—C2—C3115.78 (15)C3—C4—H4119.00
O2—C2—C3127.59 (18)C10—C4—H4119.00
C2—C3—C4120.70 (17)C6—C5—H5120.00
C2—C3—C11121.37 (16)C10—C5—H5120.00
C4—C3—C11117.82 (16)C6—C7—H7120.00
C3—C4—C10121.38 (17)C8—C7—H7120.00
C6—C5—C10119.03 (18)C7—C8—H8120.00
Cl1—C6—C5119.20 (17)C9—C8—H8120.00
Cl1—C6—C7119.32 (15)O12—C13—H13A110.00
C5—C6—C7121.48 (19)O12—C13—H13B110.00
C6—C7—C8120.04 (19)C14—C13—H13A110.00
C7—C8—C9119.0 (2)C14—C13—H13B110.00
O1—C9—C8117.64 (17)H13A—C13—H13B108.00
O1—C9—C10121.07 (16)C13—C14—H14A109.00
C8—C9—C10121.28 (18)C13—C14—H14B109.00
C4—C10—C5123.34 (17)C13—C14—H14C109.00
C4—C10—C9117.55 (17)H14A—C14—H14B109.00
C5—C10—C9119.11 (17)H14A—C14—H14C110.00
O11—C11—O12124.10 (18)H14B—C14—H14C109.00
C9—O1—C2—O2170.94 (18)C4—C3—C11—O12−159.90 (18)
C9—O1—C2—C3−7.9 (2)C3—C4—C10—C5177.27 (19)
C2—O1—C9—C8−176.03 (17)C3—C4—C10—C9−2.5 (3)
C2—O1—C9—C102.9 (3)C10—C5—C6—Cl1177.71 (15)
C13—O12—C11—O110.3 (3)C10—C5—C6—C7−1.9 (3)
C13—O12—C11—C3−179.94 (17)C6—C5—C10—C4−179.58 (19)
C11—O12—C13—C14166.4 (2)C6—C5—C10—C90.2 (3)
O1—C2—C3—C47.9 (3)Cl1—C6—C7—C8−177.82 (17)
O1—C2—C3—C11−175.94 (16)C5—C6—C7—C81.8 (3)
O2—C2—C3—C4−170.8 (2)C6—C7—C8—C90.1 (3)
O2—C2—C3—C115.4 (3)C7—C8—C9—O1177.03 (18)
C2—C3—C4—C10−2.9 (3)C7—C8—C9—C10−1.9 (3)
C11—C3—C4—C10−179.18 (17)O1—C9—C10—C42.6 (3)
C2—C3—C11—O11−156.44 (19)O1—C9—C10—C5−177.12 (17)
C2—C3—C11—O1223.8 (3)C8—C9—C10—C4−178.52 (18)
C4—C3—C11—O1119.9 (3)C8—C9—C10—C51.7 (3)
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+1, −y, −z+1; (iii) x−1, y, z; (iv) −x, y−1/2, −z+1/2; (v) −x+2, −y, −z+1; (vi) −x, y+1/2, −z+1/2; (vii) −x+1, y−1/2, −z+1/2; (viii) x+1, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C4—H4···O11v0.9302.543.346 (3)145
C5—H5···O11v0.932.433.263 (3)149
C7—H7···O2vi0.932.593.182 (3)122
C8—H8···O2vi0.932.593.182 (3)122
Symmetry codes: (v) −x+2, −y, −z+1; (vi) −x, y+1/2, −z+1/2.
(II) ethyl 6-bromo-2-oxo-2H-chromene-3-carboxylate top
Crystal data top
C12H9BrO4F(000) = 592
Mr = 297.10Dx = 1.726 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 600 reflections
a = 5.8432 (6) Åθ = 20–25°
b = 13.2073 (14) ŵ = 3.60 mm−1
c = 15.6959 (15) ÅT = 293 K
β = 109.327 (3)°Block, colorless
V = 1143.0 (2) Å30.26 × 0.15 × 0.12 mm
Z = 4
Data collection top
Bruker SMART CCD area-detector
diffractometer		2091 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.041
φ and ω scansθmax = 28.3°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		h = −7→7
Tmin = 0.455, Tmax = 0.672k = −17→17
12998 measured reflectionsl = −19→20
2754 independent reflections
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)] = 0.045Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.123H-atom parameters constrained
S = 1.05 w = 1/[σ2(Fo2) + (0.0647P)2 + 0.4243P]
where P = (Fo2 + 2Fc2)/3
2754 reflections(Δ/σ)max < 0.001
155 parametersΔρmax = 1.00 e Å−3
0 restraintsΔρmin = −0.26 e Å−3
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
Br10.84921 (6)0.44363 (2)0.37854 (3)0.0644 (1)
O10.1635 (3)0.09348 (15)0.31200 (14)0.0489 (6)
O20.0656 (4)−0.05880 (16)0.34303 (17)0.0592 (8)
O110.7741 (4)−0.13087 (16)0.48632 (15)0.0601 (7)
O120.4410 (4)−0.19686 (15)0.38850 (15)0.0583 (7)
C20.2270 (5)−0.0016 (2)0.34845 (18)0.0436 (8)
C30.4874 (5)−0.0194 (2)0.39127 (18)0.0421 (8)
C40.6471 (5)0.05665 (19)0.40357 (19)0.0426 (8)
C50.7279 (5)0.2389 (2)0.38623 (19)0.0464 (9)
C60.6385 (5)0.3310 (2)0.35353 (19)0.0457 (8)
C70.3948 (5)0.3448 (2)0.3036 (2)0.0502 (9)
C80.2387 (5)0.2639 (2)0.2888 (2)0.0499 (9)
C90.3259 (5)0.1710 (2)0.32412 (18)0.0420 (8)
C100.5710 (5)0.1565 (2)0.37181 (18)0.0416 (8)
C110.5832 (5)−0.1214 (2)0.42728 (18)0.0430 (8)
C130.5305 (7)−0.2968 (2)0.4225 (3)0.0685 (13)
C140.3306 (8)−0.3683 (3)0.3897 (3)0.0901 (18)
H40.810760.044100.433400.0511*
H50.892210.230860.417940.0557*
H70.338050.408230.280340.0603*
H80.075600.271910.255160.0599*
H13A0.59040−0.296460.487970.0825*
H13B0.66249−0.316210.401270.0825*
H14A0.28028−0.371680.325020.1351*
H14B0.19718−0.346160.407850.1351*
H14C0.38270−0.434050.414630.1351*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0588 (2)0.0472 (2)0.0825 (3)−0.0078 (1)0.0173 (2)0.0027 (2)
O10.0340 (9)0.0441 (10)0.0536 (11)0.0032 (8)−0.0058 (8)−0.0024 (9)
O20.0397 (11)0.0512 (13)0.0740 (15)−0.0034 (9)0.0019 (10)−0.0045 (10)
O110.0449 (11)0.0509 (12)0.0683 (14)0.0072 (9)−0.0031 (10)0.0129 (10)
O120.0527 (12)0.0367 (10)0.0710 (14)0.0037 (9)0.0008 (10)0.0016 (10)
C20.0365 (13)0.0417 (15)0.0433 (14)0.0013 (12)0.0008 (11)−0.0059 (12)
C30.0375 (13)0.0419 (14)0.0405 (14)0.0033 (11)0.0043 (11)−0.0006 (11)
C40.0321 (12)0.0417 (14)0.0478 (15)0.0032 (10)0.0050 (11)0.0024 (11)
C50.0332 (12)0.0496 (16)0.0502 (16)0.0023 (11)0.0055 (11)0.0030 (13)
C60.0431 (14)0.0414 (14)0.0496 (16)−0.0029 (12)0.0114 (12)0.0002 (12)
C70.0491 (15)0.0426 (15)0.0508 (16)0.0093 (12)0.0055 (12)0.0076 (12)
C80.0391 (14)0.0489 (16)0.0500 (16)0.0098 (12)−0.0011 (12)0.0020 (13)
C90.0351 (12)0.0410 (14)0.0421 (14)0.0036 (10)0.0024 (10)−0.0043 (11)
C100.0348 (12)0.0394 (14)0.0442 (14)0.0040 (10)0.0043 (10)0.0011 (11)
C110.0406 (13)0.0414 (14)0.0451 (14)0.0029 (11)0.0118 (12)0.0031 (12)
C130.0594 (19)0.0426 (17)0.090 (3)0.0066 (14)0.0064 (18)0.0068 (17)
C140.081 (3)0.049 (2)0.120 (4)−0.0077 (18)0.006 (3)0.004 (2)
Geometric parameters (Å, º) top
Br1—C61.888 (3)C7—C81.374 (4)
O1—C21.379 (3)C8—C91.373 (4)
O1—C91.366 (3)C9—C101.392 (4)
O2—C21.189 (4)C13—C141.457 (6)
O11—C111.198 (4)C4—H40.9300
O12—C111.311 (3)C5—H50.9300
O12—C131.455 (4)C7—H70.9300
C2—C31.465 (4)C8—H80.9300
C3—C41.341 (4)C13—H13A0.9700
C3—C111.496 (4)C13—H13B0.9700
C4—C101.428 (4)C14—H14A0.9600
C5—C61.356 (4)C14—H14B0.9600
C5—C101.392 (4)C14—H14C0.9600
C6—C71.392 (4)
Br1···C14i3.713 (5)C3···C4iv3.592 (4)
Br1···O1ii3.567 (2)C3···C11iv3.538 (4)
Br1···C2ii3.516 (3)C4···O2ix3.278 (4)
O1···Br1iii3.567 (2)C4···O11vii3.394 (4)
O1···O11iv3.104 (3)C4···C3iv3.592 (4)
O2···C4v3.278 (4)C4···C11iv3.458 (4)
O2···O122.759 (3)C5···O11vii3.264 (4)
O2···C8vi3.239 (4)C7···O2viii3.171 (4)
O2···C7vi3.171 (4)C8···O2viii3.239 (4)
O11···C4vii3.394 (4)C9···O11iv3.260 (4)
O11···C5vii3.264 (4)C10···C11iv3.585 (4)
O11···C2iv3.130 (3)C11···C3iv3.538 (4)
O11···C9iv3.260 (4)C11···C4iv3.458 (4)
O11···O1iv3.104 (3)C11···C10iv3.585 (4)
O12···O22.759 (3)C14···Br1x3.713 (5)
O1···H14Aviii2.8100H4···O2ix2.7300
O2···H7vi2.5500H4···O112.4900
O2···H4v2.7300H4···H52.5400
O2···H8vi2.6900H4···O11vii2.6000
O11···H13B2.7600H5···H42.5400
O11···H13A2.4400H5···O11vii2.4200
O11···H4vii2.6000H7···O2viii2.5500
O11···H5vii2.4200H8···O2viii2.6900
O11···H42.4900H13A···O112.4400
C2···Br1iii3.516 (3)H13B···O112.7600
C2···O11iv3.130 (3)H14A···O1vi2.8100
C3···C3iv3.406 (4)
C2—O1—C9123.1 (2)O11—C11—C3121.5 (3)
C11—O12—C13115.1 (3)O12—C11—C3114.1 (2)
O1—C2—O2116.8 (3)O12—C13—C14108.0 (3)
O1—C2—C3115.6 (2)C3—C4—H4119.00
O2—C2—C3127.6 (3)C10—C4—H4119.00
C2—C3—C4120.9 (2)C6—C5—H5120.00
C2—C3—C11121.3 (2)C10—C5—H5120.00
C4—C3—C11117.7 (3)C6—C7—H7120.00
C3—C4—C10121.3 (3)C8—C7—H7120.00
C6—C5—C10119.3 (3)C7—C8—H8120.00
Br1—C6—C5119.0 (2)C9—C8—H8120.00
Br1—C6—C7119.3 (2)O12—C13—H13A110.00
C5—C6—C7121.7 (3)O12—C13—H13B110.00
C6—C7—C8119.5 (3)C14—C13—H13A110.00
C7—C8—C9119.3 (3)C14—C13—H13B110.00
O1—C9—C8117.8 (3)H13A—C13—H13B108.00
O1—C9—C10121.0 (2)C13—C14—H14A109.00
C8—C9—C10121.2 (3)C13—C14—H14B109.00
C4—C10—C5123.6 (3)C13—C14—H14C109.00
C4—C10—C9117.4 (3)H14A—C14—H14B109.00
C5—C10—C9119.0 (2)H14A—C14—H14C110.00
O11—C11—O12124.4 (3)H14B—C14—H14C110.00
C9—O1—C2—O2170.7 (3)C4—C3—C11—O12−158.2 (3)
C9—O1—C2—C3−8.1 (4)C3—C4—C10—C5177.2 (3)
C2—O1—C9—C8−176.4 (3)C3—C4—C10—C9−2.7 (4)
C2—O1—C9—C102.7 (4)C10—C5—C6—Br1176.9 (2)
C13—O12—C11—O110.2 (4)C10—C5—C6—C7−1.9 (4)
C13—O12—C11—C3−180.0 (3)C6—C5—C10—C4−179.9 (3)
C11—O12—C13—C14166.1 (3)C6—C5—C10—C90.0 (4)
O1—C2—C3—C48.1 (4)Br1—C6—C7—C8−177.0 (2)
O1—C2—C3—C11−175.3 (2)C5—C6—C7—C81.7 (5)
O2—C2—C3—C4−170.5 (3)C6—C7—C8—C90.4 (4)
O2—C2—C3—C116.1 (5)C7—C8—C9—O1176.8 (3)
C2—C3—C4—C10−2.9 (4)C7—C8—C9—C10−2.4 (4)
C11—C3—C4—C10−179.7 (3)O1—C9—C10—C43.0 (4)
C2—C3—C11—O11−155.0 (3)O1—C9—C10—C5−176.9 (3)
C2—C3—C11—O1225.1 (4)C8—C9—C10—C4−178.0 (3)
C4—C3—C11—O1121.7 (4)C8—C9—C10—C52.2 (4)
Symmetry codes: (i) x+1, y+1, z; (ii) −x+1, y+1/2, −z+1/2; (iii) −x+1, y−1/2, −z+1/2; (iv) −x+1, −y, −z+1; (v) x−1, y, z; (vi) −x, y−1/2, −z+1/2; (vii) −x+2, −y, −z+1; (viii) −x, y+1/2, −z+1/2; (ix) x+1, y, z; (x) x−1, y−1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C4—H4···O11vii0.932.603.394 (3)143
C5—H5···O11vii0.932.423.264 (4)151
C7—H7···O2viii0.932.553.171 (4)125
C8—H8···O2viii0.932.693.239 (3)119
Symmetry codes: (vii) −x+2, −y, −z+1; (viii) −x, y+1/2, −z+1/2.
 

Acknowledgements

This work was supported by the SIP–IPN (Secretaría de Investigación y Posgrado del Instituto Politécnico Nacional), the CGIC–UC (Coordinación General de Investigación Cientifica de la Universidad de Colima) and PROMEP–SEP.

References

First citationAllen, F. H. (2002). Acta Cryst. B58, 380–388.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
 First citationAllen, F. H., Baalham, C. A., Lommerse, J. P. M. & Raithby, P. R. (1998). Acta Cryst. B54, 320–329.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationAuffinger, P., Hays, F. A., Westhof, E. & Ho, P. S. (2004). PNAS, 101, 16789–16794.  CrossRef PubMed CAS Google Scholar
 First citationBernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573.  CrossRef CAS Web of Science Google Scholar
 First citationBondi, A. J. (1964). Chem. Phys. 68, 441.  CrossRef Google Scholar
 First citationBonsignore, L., Cottiglia, F., Maccioni, A. & Secci, D. (1995). J. Heterocycl. Chem. 32, 573–577.  CrossRef CAS Google Scholar
 First citationBosch, E. & Barnes, C. L. (2002). Cryst. Growth Des. 2, 299–302.  Web of Science CSD CrossRef CAS Google Scholar
 First citationBruker (2002). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationBruno, I. J., Cole, J. C., Edgington, P. R., Kessler, M., Macrae, C. F., McCabe, P., Pearson, J. & Taylor, R. (2002). Acta Cryst. B58, 389–397.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
 First citationChimenti, F., Secci, D., Bolasco, A., Chimenti, P., Granese, A., Befani, O., Turín, P. & Ortuso, F. (2004). Bioorg. Med. Chem. Lett. 14, 3697–3703.  CrossRef PubMed CAS Google Scholar
 First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals Google Scholar
 First citationFujii, I., Mano, Y. & Hirayama, N. (2005). Acta Cryst. E61, o1456–o1458.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationGarcía-Báez, E. V., Martínez-Martínez, F. J., Höpfl, H. & Padilla-Martínez, I. I. (2003). Cryst. Growth Des. 3, 35–45.  Google Scholar
 First citationGnanaguru, K., Ramasubbu, N., Venkatesan, K. & Ramamurthy, V. (1985). J. Org. Chem. 50, 2337–2346.  CSD CrossRef CAS Web of Science Google Scholar
 First citationGursoy, A. & Karali, N. (2003). Turk. J. Chem. 27, 545–551.  Google Scholar
 First citationKontogiorgis, C. A. & Hadjipavlou-Litina, D. J. (2005). J. Med. Chem. 48, 6400–6408.  Web of Science CrossRef PubMed CAS Google Scholar
 First citationLacy, A. & O'Kennedy, R. (2004). Curr. Pharm. Des. 10, 3797–3811.  Web of Science CrossRef PubMed CAS Google Scholar
 First citationLee, K. H. & Morris, S. (1999). Pure Appl. Chem. 71, 1045–1051.  CAS Google Scholar
 First citationLommerse, J. P. M., Stone, A. J., Taylor, R. & Allen, F. H. (1996). J. Am. Chem. Soc. 118, 3108–3116.  CSD CrossRef CAS Web of Science Google Scholar
 First citationMagaña-Vergara, N. E., Martínez-Martínez, F. J., Padilla-Martínez, I. I., Höpfl, H. & García-Báez, E. V. (2004). Acta Cryst. E60, o2306–o2308.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationMarchi, A. A. de, Castilho, M. S., Nascimento, P. G. B., Archanjo, F. C., Del Ponte, G., Oliva, G. & Pupo, M. T. (2004). Bioorg. Med. Chem. 12, 4823–4833.  PubMed Google Scholar
 First citationOuvrard, C., Le Questel, J.-Y., Berthelot, M. & Laurence, C. (2003). Acta Cryst. B59, 512–526.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationSantana, L., Uriarte, E., Gonzalez, H., Zagotto, G., Soto, R. & Mendez, E. (2006). J. Med. Chem. 49, 1149–1156.  CrossRef PubMed CAS Google Scholar
 First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
 First citationSheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.  Google Scholar
 First citationUmezawa, Y., Tsuboyama, S., Honda, K., Uzawa, J. & Nishio, M. (1998). Bull. Chem. Soc. Jpn, 71, 1207–1213.  Web of Science CrossRef CAS Google Scholar

© International Union of Crystallography. Prior permission is not required to reproduce short quotations, tables and figures from this article, provided the original authors and source are cited. For more information, click here.

Journal logoSTRUCTURAL
CHEMISTRY
ISSN: 2053-2296
Volume 63| Part 4| April 2007| Pages o239-o242
https://doi.org/10.1107/S0108270107008712
Follow Acta Cryst. C
Sign up for e-alerts
E-alerts
Follow Acta Cryst. on Twitter
Twitter
Follow us on facebook
Facebook
Sign up for RSS feeds
RSS