N-Butyl-4-chloro­benzamide

Saeed, A.; Khera, R.A.; Abbas, N.; Simpson, J.; Stanley, R.G.

doi:10.1107/S1600536808036313

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 64| Part 12| December 2008| Pages o2322-o2323

doi:10.1107/S1600536808036313

Open

access

N-Butyl-4-chlorobenzamide

Aamer Saeed,^a ^* Rasheed Ahmad Khera,^a Naeem Abbas,^a Jim Simpson ^b and Roderick G. Stanley ^b

^aDepartment of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan, and ^bDepartment of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand
^*Correspondence e-mail: aamersaeed@yahoo.com

(Received 11 October 2008; accepted 6 November 2008; online 13 November 2008)

In the title benzamide derivative, C₁₁H₁₄ClNO, the chlorobenzene and butylamine groups are each planar, with mean deviations from the planes of 0.013 and 0.030 Å, respectively, and a dihedral angle of 2.54 (9)° between the two planes. In the crystal structure, N—H⋯O hydrogen bonds link molecules in rows along a. Short intermolecular Cl⋯Cl interactions [3.4225 (5) Å] link these rows into sheets in the ac plane. Additional weak C—H⋯O and C—H⋯π interactions generate a three-dimensional network.

Related literature

For details of the biological activity of benzanilides, see: Olsson et al., (2002 ); Lindgren et al. (2001 ); Calderone et al. (2006 ). For the use of benzamides in organic synthesis, see: Reinaud et al. (1991 ); Zhichkin et al. (2007 ); Beccalli et al. (2005 ); For the fluorescence properties of benzanilides, see: Lewis & Long (1998 ). For related structures see: Saeed et al. (2008 ); Hempel et al. (2005 ). For reference structural data, see: Allen et al. (1987 ). For related literature, see: Vega-Noverola et al. (1989 ); Yoo et al. (2005 ).

Experimental

Crystal data

C₁₁H₁₄ClNO
M_r = 211.68
Triclinic, $[P \overline 1]$
a = 5.1702 (4) Å
b = 7.8979 (5) Å
c = 13.2978 (9) Å
α = 89.275 (3)°
β = 84.863 (4)°
γ = 77.165 (4)°
V = 527.29 (6) Å³
Z = 2
Mo Kα radiation
μ = 0.33 mm⁻¹
T = 81 (2) K
0.42 × 0.30 × 0.08 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2006 ) T_min = 0.820, T_max = 0.974
6632 measured reflections
3445 independent reflections
3050 reflections with I > 2σ(I)
R_int = 0.017

Refinement

R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.090
S = 1.04
3445 reflections
132 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.43 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—HN1⋯O1ⁱ	0.831 (15)	2.203 (15)	3.0164 (10)	166.3 (13)
C3—H3⋯O1ⁱⁱ	0.95	2.66	3.3146 (11)	127
C8—H8A⋯Cg1ⁱⁱⁱ	0.99	2.84	3.697 (16)	145
Symmetry codes: (i) x+1, y, z; (ii) -x, -y+2, -z; (iii) -x+1, -y, -z. Cg1 is the centroid of the C2–C7 benzene ring.

Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 and SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and TITAN2000 (Hunter & Simpson, 1999 ); molecular graphics: ORTEP-3 (Farrugia, 1997 ) and Mercury (Macrae et al., 2006 ); software used to prepare material for publication: SHELXL97, enCIFer (Allen et al., 2004 ), PLATON (Spek, 2003 ) and publCIF (Westrip, 2008 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808036313/sg2272sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808036313/sg2272Isup2.hkl

checkCIF report

Comment top

The benzanilide core is present in compounds with such a wide range of biological activities that it has been called a privileged structure. N-substituted benzamides are well known anticancer compounds and the mechanism of action for N-substituted benzamide-induced apoptosis has been studied, using declopramide as a lead compound (Olsson et al., 2002). N-substituted benzamides inhibit the activity of nuclear factor- B and nuclear factor of activated T cells activity while inducing activator protein 1 activity in T lymphocytes (Lindgren et al., 2001). Various N-substituted benzamides exhibit potent antiemetic activity (Vega-noverola et al., 1989), while heterocyclic analogs of benzanilide derivatives are potassium channel activators (Calderone et al., 2006). o-Aryloxylation of N-substituted benzamides induced by the copper(II)/trimethylamine N-oxide system has been studied (Reinaud et al., 1991). N-Alkylated 2-nitrobenzamides are intermediates in the synthesis of dibenzo[b,e][1,4]diazepines (Zhichkin et al., 2007) and N-Acyl-2-nitrobenzamides are precursors of 2,3-disubstitued 3H-quinazoline-4-ones (Beccalli et al., 2005). A one-pot conversion of 2-nitro-n-arylbenzamides to 2,3-dihydro-1H-quinazoline-4-ones has also been reported (Yoo et al., 2005). The anomalous dual fluorescence of benzanilides has been assigned to the two lowest benzanilide singlet states (Lewis & Long, 1998)

As part of our work on the structure of benzanildes and related compounds, we report here the structure of the title benzamide derivative, I, Fig. 1. The C1···C7/Cl system is planar with a maximum deviation of 0.0161 (7) Å from the least squares plane. The carbonyl oxygen atom O1 is displaced by 0.6102 (10) Å from this plane. The butylamine N1/C8···C11 fragment is also planar, maximum deviation 0.0365 (7) Å for C9. The dihedral angle between these two planes is 2.54 (9) °. Bond distances within the molecule are normal (Allen et al., 1987) and similar to those found in the structures of related 4-chlorobenzamide derivatives (Saeed et al., 2008, Hempel et al., 2005).

In the crystal structure N1—HN1···O1 hydrogen bonds, Table 1, link molecules into rows along a. Cl1···Cl1 interactions at 3.4225 (5) Å bridge these rows to form sheets in the ac plane, Fig. 2. The sheets are interconnected by weak C3—H3···O1 hydrogen bonds and C8—H8···π interactions involving the C2···C7 benzene ring to generate a three dimensional network, Fig. 3.

Related literature top

For details of the biological activity of benzanilides, see: Olsson et al., (2002); Lindgren et al. (2001); Calderone et al. (2006). For the use of benzamides in organic synthesis, see: Reinaud et al. (1991); Zhichkin et al. (2007); Beccalli et al. (2005); For the fluorescence properties of benzanilides, see: (Lewis & Long, 1998). For related structures see: Saeed et al. (2008); Hempel et al. (2005). For reference structural data, see: Allen et al. (1987). For related literature, see: Vega-noverola et al. (1989); Yoo et al. (2005). Cg1 is the centroid of the C2–C7 benzene ring.

Experimental top

2-Fluorobenzoyl chloride (1 mmol) in CHCl₃ was treated with cyclohexyl amine (3.5 mmol) under a nitrogen atmosphere at reflux for 5 h. Upon cooling, the reaction mixture was diluted with CHCl₃ and washed consecutively with 1 M aq HCl and saturated aq NaHCO₃. The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. Crystallization of the residue in ethanol afforded the title compound (79 %) as white needles: Anal. calcd. for C₁₁H₁₄ClNO: C 62.41, H 6.67, N 6.62%; found: C 62.34, H 7.16, N 6.57%.

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 (Bruker, 2006) and SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and TITAN (Hunter & Simpson, 1999); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), enCIFer (Allen et al., 2004), PLATON (Spek, 2003) and publCIF (Westrip, 2008).

Figures top

	Fig. 1. The structure of I showing the atom numbering with displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. Sheets of molecules of I formed in the ac plane by N—H···O hydrogen bonds and Cl···Cl interactions.
	Fig. 3. Crystal packing of I viewed down the b axis.

N-Butyl-4-chlorobenzamide top

Crystal data top

C₁₁H₁₄ClNO	Z = 2
M_r = 211.68	F(000) = 224
Triclinic, P1	D_x = 1.333 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.1702 (4) Å	Cell parameters from 3494 reflections
b = 7.8979 (5) Å	θ = 5.3–66.2°
c = 13.2978 (9) Å	µ = 0.33 mm⁻¹
α = 89.275 (3)°	T = 81 K
β = 84.863 (4)°	Irregular fragment, colourless
γ = 77.165 (4)°	0.42 × 0.30 × 0.08 mm
V = 527.29 (6) Å³

Data collection top

Bruker APEXII CCD area-detector diffractometer	3445 independent reflections
Radiation source: fine-focus sealed tube	3050 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.017
ω scans	θ_max = 33.1°, θ_min = 3.1°
Absorption correction: multi-scan (SADABS; Bruker, 2006)	h = −7→6
T_min = 0.820, T_max = 0.974	k = −11→11
6632 measured reflections	l = −20→20

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.090	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ²(F_o²) + (0.0471P)² + 0.125P] where P = (F_o² + 2F_c²)/3
3445 reflections	(Δ/σ)_max = 0.002
132 parameters	Δρ_max = 0.43 e Å⁻³
0 restraints	Δρ_min = −0.22 e Å⁻³

Crystal data top

C₁₁H₁₄ClNO	γ = 77.165 (4)°
M_r = 211.68	V = 527.29 (6) Å³
Triclinic, P1	Z = 2
a = 5.1702 (4) Å	Mo Kα radiation
b = 7.8979 (5) Å	µ = 0.33 mm⁻¹
c = 13.2978 (9) Å	T = 81 K
α = 89.275 (3)°	0.42 × 0.30 × 0.08 mm
β = 84.863 (4)°

Data collection top

Bruker APEXII CCD area-detector diffractometer	3445 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2006)	3050 reflections with I > 2σ(I)
T_min = 0.820, T_max = 0.974	R_int = 0.017
6632 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	0 restraints
wR(F²) = 0.090	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	Δρ_max = 0.43 e Å⁻³
3445 reflections	Δρ_min = −0.22 e Å⁻³
132 parameters

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.

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 > 2sigma(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

	x	y	z	U_iso*/U_eq
N1	0.51637 (16)	0.82511 (10)	−0.10915 (6)	0.01587 (15)
HN1	0.662 (3)	0.8260 (18)	−0.0876 (11)	0.026 (3)*
C1	0.31476 (17)	0.79695 (10)	−0.04475 (6)	0.01281 (15)
O1	0.08420 (13)	0.81551 (8)	−0.06861 (5)	0.01616 (14)
C2	0.38267 (17)	0.73835 (10)	0.05917 (6)	0.01257 (15)
C3	0.18549 (19)	0.78474 (11)	0.13885 (7)	0.01611 (17)
H3	0.0169	0.8545	0.1262	0.019*
C4	0.2331 (2)	0.73001 (12)	0.23650 (7)	0.01847 (18)
H4	0.0995	0.7631	0.2908	0.022*
C5	0.4800 (2)	0.62579 (11)	0.25329 (7)	0.01667 (17)
Cl1	0.54360 (5)	0.55693 (3)	0.375283 (17)	0.02530 (8)
C6	0.67765 (19)	0.57568 (12)	0.17528 (7)	0.01740 (17)
H6	0.8439	0.5027	0.1879	0.021*
C7	0.62886 (18)	0.63406 (11)	0.07801 (7)	0.01532 (16)
H7	0.7642	0.6026	0.0241	0.018*
C8	0.47533 (19)	0.87979 (13)	−0.21289 (7)	0.01730 (17)
H8A	0.4281	1.0082	−0.2152	0.021*
H8B	0.3242	0.8363	−0.2352	0.021*
C9	0.72100 (18)	0.81319 (12)	−0.28494 (7)	0.01526 (16)
H9A	0.7664	0.6847	−0.2840	0.018*
H9B	0.8733	0.8549	−0.2623	0.018*
C10	0.67469 (19)	0.87506 (12)	−0.39261 (7)	0.01705 (17)
H10A	0.5112	0.8435	−0.4123	0.020*
H10B	0.6458	1.0032	−0.3943	0.020*
C11	0.9070 (2)	0.79692 (14)	−0.46899 (8)	0.02213 (19)
H11A	1.0696	0.8277	−0.4500	0.033*
H11B	0.8691	0.8425	−0.5363	0.033*
H11C	0.9317	0.6703	−0.4698	0.033*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0106 (3)	0.0251 (4)	0.0134 (3)	−0.0064 (3)	−0.0033 (3)	0.0048 (3)
C1	0.0120 (4)	0.0133 (3)	0.0131 (4)	−0.0024 (3)	−0.0018 (3)	0.0006 (3)
O1	0.0097 (3)	0.0217 (3)	0.0170 (3)	−0.0028 (2)	−0.0029 (2)	0.0024 (2)
C2	0.0115 (4)	0.0138 (3)	0.0131 (4)	−0.0038 (3)	−0.0025 (3)	0.0013 (3)
C3	0.0132 (4)	0.0188 (4)	0.0154 (4)	−0.0017 (3)	−0.0005 (3)	0.0009 (3)
C4	0.0185 (4)	0.0224 (4)	0.0140 (4)	−0.0043 (3)	0.0006 (3)	0.0006 (3)
C5	0.0213 (4)	0.0170 (4)	0.0138 (4)	−0.0074 (3)	−0.0055 (3)	0.0036 (3)
Cl1	0.03326 (15)	0.02986 (13)	0.01517 (12)	−0.00986 (10)	−0.00874 (9)	0.00705 (8)
C6	0.0160 (4)	0.0180 (4)	0.0184 (4)	−0.0030 (3)	−0.0058 (3)	0.0038 (3)
C7	0.0117 (4)	0.0177 (4)	0.0159 (4)	−0.0019 (3)	−0.0015 (3)	0.0016 (3)
C8	0.0121 (4)	0.0261 (4)	0.0137 (4)	−0.0040 (3)	−0.0022 (3)	0.0059 (3)
C9	0.0115 (4)	0.0202 (4)	0.0143 (4)	−0.0034 (3)	−0.0028 (3)	0.0018 (3)
C10	0.0138 (4)	0.0230 (4)	0.0139 (4)	−0.0032 (3)	−0.0020 (3)	0.0029 (3)
C11	0.0185 (5)	0.0300 (5)	0.0170 (4)	−0.0043 (4)	0.0006 (3)	−0.0014 (3)

Geometric parameters (Å, º) top

N1—C1	1.3446 (12)	C6—H6	0.9500
N1—C8	1.4598 (11)	C7—H7	0.9500
N1—HN1	0.831 (15)	C8—C9	1.5185 (13)
C1—O1	1.2378 (11)	C8—H8A	0.9900
C1—C2	1.4984 (12)	C8—H8B	0.9900
C2—C3	1.3952 (12)	C9—C10	1.5290 (12)
C2—C7	1.3955 (12)	C9—H9A	0.9900
C3—C4	1.3891 (13)	C9—H9B	0.9900
C3—H3	0.9500	C10—C11	1.5242 (13)
C4—C5	1.3918 (13)	C10—H10A	0.9900
C4—H4	0.9500	C10—H10B	0.9900
C5—C6	1.3848 (14)	C11—H11A	0.9800
C5—Cl1	1.7405 (9)	C11—H11B	0.9800
C6—C7	1.3931 (12)	C11—H11C	0.9800

C1—N1—C8	121.48 (8)	N1—C8—C9	112.18 (7)
C1—N1—HN1	119.5 (10)	N1—C8—H8A	109.2
C8—N1—HN1	118.4 (10)	C9—C8—H8A	109.2
O1—C1—N1	122.89 (8)	N1—C8—H8B	109.2
O1—C1—C2	120.60 (8)	C9—C8—H8B	109.2
N1—C1—C2	116.51 (8)	H8A—C8—H8B	107.9
C3—C2—C7	119.40 (8)	C8—C9—C10	111.15 (7)
C3—C2—C1	117.87 (8)	C8—C9—H9A	109.4
C7—C2—C1	122.67 (8)	C10—C9—H9A	109.4
C4—C3—C2	120.71 (8)	C8—C9—H9B	109.4
C4—C3—H3	119.6	C10—C9—H9B	109.4
C2—C3—H3	119.6	H9A—C9—H9B	108.0
C3—C4—C5	118.78 (9)	C11—C10—C9	112.75 (8)
C3—C4—H4	120.6	C11—C10—H10A	109.0
C5—C4—H4	120.6	C9—C10—H10A	109.0
C6—C5—C4	121.65 (8)	C11—C10—H10B	109.0
C6—C5—Cl1	118.96 (7)	C9—C10—H10B	109.0
C4—C5—Cl1	119.39 (7)	H10A—C10—H10B	107.8
C5—C6—C7	118.95 (8)	C10—C11—H11A	109.5
C5—C6—H6	120.5	C10—C11—H11B	109.5
C7—C6—H6	120.5	H11A—C11—H11B	109.5
C6—C7—C2	120.49 (9)	C10—C11—H11C	109.5
C6—C7—H7	119.8	H11A—C11—H11C	109.5
C2—C7—H7	119.8	H11B—C11—H11C	109.5

C8—N1—C1—O1	−0.14 (13)	C3—C4—C5—Cl1	179.68 (7)
C8—N1—C1—C2	179.00 (8)	C4—C5—C6—C7	1.22 (14)
O1—C1—C2—C3	−30.72 (12)	Cl1—C5—C6—C7	−178.56 (7)
N1—C1—C2—C3	150.11 (8)	C5—C6—C7—C2	−1.35 (13)
O1—C1—C2—C7	146.41 (9)	C3—C2—C7—C6	0.37 (13)
N1—C1—C2—C7	−32.76 (12)	C1—C2—C7—C6	−176.72 (8)
C7—C2—C3—C4	0.79 (13)	C1—N1—C8—C9	−149.00 (8)
C1—C2—C3—C4	178.01 (8)	N1—C8—C9—C10	−178.91 (7)
C2—C3—C4—C5	−0.92 (14)	C8—C9—C10—C11	−174.52 (8)
C3—C4—C5—C6	−0.10 (14)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—HN1···O1ⁱ	0.831 (15)	2.203 (15)	3.0164 (10)	166.3 (13)
C3—H3···O1ⁱⁱ	0.95	2.66	3.3146 (11)	127
C8—H8A···Cg1ⁱⁱⁱ	0.99	2.84	3.697 (16)	145

Symmetry codes: (i) x+1, y, z; (ii) −x, −y+2, −z; (iii) −x+1, −y, −z.

Experimental details

Crystal data
Chemical formula	C₁₁H₁₄ClNO
M_r	211.68
Crystal system, space group	Triclinic, P1
Temperature (K)	81
a, b, c (Å)	5.1702 (4), 7.8979 (5), 13.2978 (9)
α, β, γ (°)	89.275 (3), 84.863 (4), 77.165 (4)
V (Å³)	527.29 (6)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.33
Crystal size (mm)	0.42 × 0.30 × 0.08

Data collection
Diffractometer	Bruker APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2006)
T_min, T_max	0.820, 0.974
No. of measured, independent and observed [I > 2σ(I)] reflections	6632, 3445, 3050
R_int	0.017
(sin θ/λ)_max (Å⁻¹)	0.768

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.090, 1.04
No. of reflections	3445
No. of parameters	132
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.43, −0.22

Computer programs: , APEX2 (Bruker, 2006) and SAINT (Bruker, 2006), SAINT (Bruker, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and TITAN (Hunter & Simpson, 1999), ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006), SHELXL97 (Sheldrick, 2008), enCIFer (Allen et al., 2004), PLATON (Spek, 2003) and publCIF (Westrip, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—HN1···O1ⁱ	0.831 (15)	2.203 (15)	3.0164 (10)	166.3 (13)
C3—H3···O1ⁱⁱ	0.95	2.66	3.3146 (11)	126.7
C8—H8A···Cg1ⁱⁱⁱ	0.99	2.84	3.697 (16)	145

Symmetry codes: (i) x+1, y, z; (ii) −x, −y+2, −z; (iii) −x+1, −y, −z.

Acknowledgements

NA gratefully acknowledges financial support for a PhD programme by the Higher Education Commission of Pakistan. We also thank the University of Otago for purchase of the diffractometer.

References

Allen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335–338. Web of Science CrossRef CAS IUCr Journals Google Scholar
Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
Beccalli, E. M., Broggini, G., Paladinoa, G. & Zonia, C. (2005). Tetrahedron, 61, 61–68. Web of Science CrossRef CAS Google Scholar
Bruker (2006). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Calderone, V., Fiamingo, F. L., Giorgi, I., Leonardi, M., Livi, O., Martelli, A. & Martinotti, E. (2006). Eur. J. Med. Chem. 41, 761–767. Web of Science CrossRef PubMed CAS Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Hempel, A., Camerman, N., Mastropaolo, D. & Camerman, A. (2005). Acta Cryst. E61, o2283–o2285. Web of Science CSD CrossRef IUCr Journals Google Scholar
Hunter, K. A. & Simpson, J. (1999). TITAN2000. University of Otago, New Zealand. Google Scholar
Lewis, F. D. & Long, T. M. (1998). J. Phys. Chem. A, 102, 5327–5332. Web of Science CrossRef CAS Google Scholar
Lindgren, H., Pero, R. W., Ivars, F. & Leanderson, T. (2001). Mol. Immunol. 38, 267–277. Web of Science CrossRef PubMed CAS Google Scholar
Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457. Web of Science CrossRef CAS IUCr Journals Google Scholar
Olsson, A. R., Lindgren, H., Pero, R. W. & Leanderson, T. (2002). Br. J. Cancer, 86, 971–978. Web of Science CrossRef PubMed CAS Google Scholar
Reinaud, O., Capdevielle, P. & Maumy, M. (1991). J. Chem. Soc. Perkin Trans. 1, pp. 2129–2134,. CrossRef Web of Science Google Scholar
Saeed, A., Khera, R. A., Abbas, N., Simpson, J. & Stanley, R. G. (2008). Acta Cryst. E64, o1976. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Web of Science CrossRef CAS IUCr Journals Google Scholar
Vega-Noverola, A. P., Soto, J. M., Noguera, F. P., Mauri, J. M. & Spickett, G. W. R. (1989). US Patent No. 4 877 780. Google Scholar
Westrip, S. P. (2008). publCIF. In preparation. Google Scholar
Yoo, C. L., Fettinger, J. C. & Kurth, M. J. (2005). J. Org. Chem. 70, 6941–6943. Web of Science CSD CrossRef PubMed CAS Google Scholar
Zhichkin, P., Kesicki, E., Treiberg, J., Bourdon, L., Ronsheim, M., Ooi, H. C., White, S., Judkins, A. & Fairfax, D. (2007). Org. Lett. 9, 1415–1418. Web of Science CrossRef PubMed CAS Google Scholar