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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 64| Part 8| August 2008| Pages o1501-o1502

Ethyl 3-nitro-4-(propyl­amino)benzoate

aSchool of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, bSchool of Chemical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and cX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
*Correspondence e-mail: hkfun@usm.my

(Received 8 July 2008; accepted 9 July 2008; online 16 July 2008)

In the title compound, C12H16N2O4, intra­molecular N—H⋯O and C—H⋯O hydrogen bonds generate S(6) and S(5) ring motifs, respectively. The nitro group is almost coplanar with the benzene ring, forming a dihedral angle of 6.2 (2)°. In the crystal structure, neighbouring mol­ecules are linked together by inter­molecular N—H⋯O and O⋯O inter­actions. Of interest are the short inter­molecular O⋯O inter­actions which cause a stacking arrangement of the mol­ecules along the a axis.

Related literature

For related literature on hydrogen-bond motifs, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chamg, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]). For bond-length data, see: Allen et al. (1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-S19.]). For related literature, see: Ishida et al. (2006[Ishida, T., Suzuki, T., Hirashima, S., Mizutani, K., Yoshida, A., Ando, I., Ikeda, S., Adachi, T. & Hashimoto, H. (2006). Bioorg. Med. Chem. Lett. 16, 1859-1863.]); Vinodkumar et al. (2008[Vinodkumar, R., Vaidya, S. D., Kumar, B. V. S., Bhise, U. N., Bhirud, S. B. & Mashelkar, U. C. (2008). Eur. J. Med. Chem. 43, 986-995.]). Rida et al. (2005[Rida, S. M., Ashour, F. A., El-Hawash, S. A. M., ElSemary, M. M., Badr, M. H. & Shalaby, M. A. (2005). Eur. J. Med. Chem. 40, 949-959.]); Harikrishnan et al. (2008[Harikrishnan, L. S., Kamau, M. G., Herpin, T. F., Morton, G. C., Liu, Y., Cooper, C. B., Salvati, M. E., Qiao, J. X., Wang, T. C., Adam, L. P., Taylor, D. S., Chen, A. Y. A., Yin, X., Seethala, R., Peterson, T. L. et al. (2008). Bioorg. Med. Chem. Lett. 18, 2640-2644.]); Moore et al. (2005[Moore, J. L., Taylor, S. M. & Soloshonok, V. A. (2005). Arkivoc (vi), 287-292.]).

[Scheme 1]

Experimental

Crystal data
  • C12H16N2O4

  • Mr = 252.27

  • Triclinic, [P \overline 1]

  • a = 4.4914 (4) Å

  • b = 12.0828 (9) Å

  • c = 12.8763 (9) Å

  • α = 62.494 (4)°

  • β = 81.055 (4)°

  • γ = 83.494 (4)°

  • V = 611.57 (8) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 100.0 (1) K

  • 0.51 × 0.26 × 0.26 mm

Data collection
  • Bruker SMART APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.949, Tmax = 0.974

  • 12286 measured reflections

  • 2372 independent reflections

  • 1946 reflections with I > 2σ(I)

  • Rint = 0.041

Refinement
  • R[F2 > 2σ(F2)] = 0.076

  • wR(F2) = 0.252

  • S = 1.17

  • 2372 reflections

  • 169 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.47 e Å−3

  • Δρmin = −0.33 e Å−3

Table 1
Selected interatomic distances (Å)

O1⋯O1i 2.914 (5)
O1⋯O1ii 2.984 (5)
Symmetry codes: (i) -x, -y+1, -z+1; (ii) -x+1, -y+1, -z+1.

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1N1⋯O1 0.85 (5) 2.00 (6) 2.633 (5) 131 (5)
N1—H1N1⋯O1i 0.85 (5) 2.28 (5) 2.998 (4) 141 (5)
C2—H2A⋯O2 0.93 2.35 2.674 (4) 100
Symmetry code: (i) -x, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]).

Supporting information


Comment top

The benzoic acid cores are precursors to many medicinally important heterocycles, e.g. benzimidazoles (Ishida et al., 2006; Vinodkumar et al., 2008) and benzoxazoles (Rida et al., 2005; Harikrishnan et al., 2008). Using Moore's procedure (Moore et al., 2005) with some modifications, we attempted the derivatization of nitro benzoic acid precursors, which led to the synthesis of the title compound (I) bearing a propylamine motif. Its crystal structure has been determined and is presented here.

In the title compound (I), (Fig. 1), intramolecular N—H···O and C—H···O hydrogen bonds generate S(6) and S(5) ring motifs, respectively (Bernstein et al., 1995). The bond lengths and angles are within normal ranges (Allen et al., 1987).The nitro group is almost coplanar with the benzene ring with torsion angle of -6.4 (5)°. In the crystal structure (Fig. 2), neighbouring molecules are linked together by intermolecular N—H···O and O···O interactions. The interesting feature of the crystal structure is the short intermolecular O···O [symmetry codes: -x, 1 - y, 1 - z; 1 - x, 1 - y, 1 - z] interactions (Table 2) with distances of 2.914 (5) and 2.984 (5) Å which are shorter than the sum of the van der Waals radii of oxygen atoms. These interactions along with the intermolecular N—H···O interactions stack the molecules along the a axis.

Related literature top

For related literature on hydrogen-bond motifs, see: Bernstein et al. (1995). For bond-length data, see: Allen et al. (1987). For related literature, see: Ishida et al. (2006); Vinodkumar et al. (2008). Rida et al. (2005); Harikrishnan et al. (2008); Moore et al. (2005).

Experimental top

The title compound (I) was synthesized by adding N,N-diisopropyl ethylamine (DIPEA) (0.20 ml, 1.12 mmol) dropwise to a stirred solution of ethyl 4-fluoro-3-nitrobenzoate (200 mg, 0.93 mmol) in dry dichloromethane (10 ml). Propylamine (0.10 ml, 1.03 mmol) was added slowly with stirring, and then the mixture was stirred overnight at room temperature under N2. After completion of the reaction, the mixture was washed with 10% Na2CO3 (10 ml). The aqueous layer was washed again with dichloromethane (3 x 15 ml). The organic fractions were pooled and dried over MgSO4 and the solvent was removed by rotary evaporator. Recrystallization with hot hexane afforded the desired compound (I) as yellow needle-like crystals.

Refinement top

The H-atom bound to N1 was located from the difference Fourier map and refined freely. The rest of the hydrogen atoms were positioned geometrically [C—H = 0.93–0.97 Å] and refined using a riding model with Uiso = 1.2 or 1.5Ueq(C). A rotating-group model was used for the methyl groups.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2 (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atomic numbering. Intramolecular hydrogen bonds are drawn as dashed lines.
[Figure 2] Fig. 2. The crystal packing of (I), showing stacking arrangement viewed down the a-axis. Intramolecular and intermolecular interactions are drawn as dashed lines.
Ethyl 3-nitro-4-(propylamino)benzoate top
Crystal data top
C12H16N2O4Z = 2
Mr = 252.27F(000) = 268
Triclinic, P1Dx = 1.370 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 4.4914 (4) ÅCell parameters from 6896 reflections
b = 12.0828 (9) Åθ = 3.2–33.0°
c = 12.8763 (9) ŵ = 0.10 mm1
α = 62.494 (4)°T = 100 K
β = 81.055 (4)°Needle, yellow
γ = 83.494 (4)°0.51 × 0.26 × 0.26 mm
V = 611.57 (8) Å3
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
2372 independent reflections
Radiation source: fine-focus sealed tube1946 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.041
ϕ and ω scansθmax = 26.0°, θmin = 1.8°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
h = 55
Tmin = 0.949, Tmax = 0.974k = 1414
12286 measured reflectionsl = 1515
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)] = 0.076Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.252H atoms treated by a mixture of independent and constrained refinement
S = 1.17 w = 1/[σ2(Fo2) + (0.1098P)2 + 1.609P]
where P = (Fo2 + 2Fc2)/3
2372 reflections(Δ/σ)max < 0.001
169 parametersΔρmax = 0.47 e Å3
0 restraintsΔρmin = 0.33 e Å3
Crystal data top
C12H16N2O4γ = 83.494 (4)°
Mr = 252.27V = 611.57 (8) Å3
Triclinic, P1Z = 2
a = 4.4914 (4) ÅMo Kα radiation
b = 12.0828 (9) ŵ = 0.10 mm1
c = 12.8763 (9) ÅT = 100 K
α = 62.494 (4)°0.51 × 0.26 × 0.26 mm
β = 81.055 (4)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
2372 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
1946 reflections with I > 2σ(I)
Tmin = 0.949, Tmax = 0.974Rint = 0.041
12286 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0760 restraints
wR(F2) = 0.252H atoms treated by a mixture of independent and constrained refinement
S = 1.17Δρmax = 0.47 e Å3
2372 reflectionsΔρmin = 0.33 e Å3
169 parameters
Special details top

Experimental. The low-temperature data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.

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
O10.2464 (7)0.4136 (3)0.5558 (2)0.0326 (7)
O20.5971 (6)0.2725 (2)0.6301 (2)0.0316 (7)
O30.8766 (6)0.1455 (2)1.0099 (2)0.0239 (6)
O40.7178 (6)0.2578 (2)1.1092 (2)0.0272 (6)
N10.0274 (7)0.5600 (3)0.6530 (3)0.0217 (7)
N20.4117 (7)0.3535 (3)0.6346 (3)0.0228 (7)
C10.3823 (8)0.3799 (3)0.7345 (3)0.0195 (7)
C20.5528 (8)0.3013 (3)0.8258 (3)0.0200 (7)
H2A0.67750.23740.81920.024*
C30.5379 (8)0.3177 (3)0.9255 (3)0.0200 (7)
C40.3490 (8)0.4159 (3)0.9327 (3)0.0210 (7)
H4A0.33580.42740.99990.025*
C50.1849 (8)0.4945 (3)0.8436 (3)0.0215 (7)
H5A0.06500.55890.85120.026*
C60.1917 (8)0.4809 (3)0.7389 (3)0.0203 (7)
C70.1636 (8)0.6655 (3)0.6552 (3)0.0223 (7)
H7A0.27550.63880.73300.027*
H7B0.30860.68950.59910.027*
C80.0108 (8)0.7792 (3)0.6262 (3)0.0238 (8)
H8A0.15180.75720.68340.029*
H8B0.12510.80650.54880.029*
C90.2061 (9)0.8850 (3)0.6280 (3)0.0281 (8)
H9A0.09320.95320.61690.042*
H9B0.33040.85570.70250.042*
H9C0.33130.91260.56570.042*
C100.7166 (8)0.2397 (3)1.0240 (3)0.0212 (7)
C111.0559 (8)0.0633 (3)1.1042 (3)0.0253 (8)
H11A1.13450.11151.13580.030*
H11B1.22570.02611.07280.030*
C120.8678 (9)0.0386 (3)1.2015 (3)0.0292 (8)
H12A0.99260.09431.26070.044*
H12B0.78370.08431.16960.044*
H12C0.70770.00201.23610.044*
H1N10.031 (11)0.547 (4)0.593 (5)0.038 (13)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0432 (16)0.0348 (15)0.0271 (14)0.0142 (12)0.0198 (12)0.0189 (12)
O20.0420 (16)0.0317 (14)0.0240 (14)0.0155 (12)0.0099 (11)0.0171 (11)
O30.0281 (13)0.0254 (13)0.0187 (12)0.0036 (10)0.0072 (10)0.0099 (10)
O40.0372 (15)0.0284 (13)0.0185 (12)0.0009 (11)0.0075 (10)0.0120 (11)
N10.0265 (16)0.0218 (14)0.0198 (15)0.0033 (12)0.0064 (12)0.0117 (12)
N20.0290 (16)0.0206 (14)0.0189 (14)0.0030 (12)0.0069 (12)0.0087 (12)
C10.0248 (17)0.0185 (16)0.0145 (16)0.0023 (13)0.0022 (13)0.0065 (13)
C20.0232 (17)0.0182 (15)0.0186 (16)0.0010 (13)0.0024 (13)0.0084 (13)
C30.0211 (17)0.0211 (16)0.0170 (16)0.0035 (13)0.0014 (13)0.0077 (13)
C40.0275 (18)0.0212 (16)0.0143 (15)0.0045 (13)0.0003 (13)0.0080 (13)
C50.0228 (17)0.0216 (16)0.0201 (17)0.0017 (13)0.0005 (13)0.0100 (14)
C60.0200 (16)0.0200 (16)0.0199 (17)0.0032 (13)0.0015 (13)0.0080 (13)
C70.0235 (17)0.0215 (17)0.0219 (17)0.0052 (13)0.0060 (13)0.0101 (14)
C80.0248 (18)0.0235 (17)0.0215 (17)0.0016 (14)0.0030 (13)0.0094 (14)
C90.033 (2)0.0240 (18)0.0261 (19)0.0008 (15)0.0019 (15)0.0112 (15)
C100.0228 (17)0.0204 (16)0.0188 (16)0.0036 (13)0.0012 (13)0.0074 (13)
C110.0249 (18)0.0290 (18)0.0208 (17)0.0048 (14)0.0080 (14)0.0101 (15)
C120.034 (2)0.0262 (18)0.0247 (19)0.0051 (15)0.0066 (15)0.0101 (15)
Geometric parameters (Å, º) top
O1—N21.241 (4)C5—C61.426 (5)
O2—N21.228 (4)C5—H5A0.9300
O3—C101.345 (4)C7—C81.524 (5)
O3—C111.455 (4)C7—H7A0.9700
O4—C101.214 (4)C7—H7B0.9700
N1—C61.342 (4)C8—C91.523 (5)
N1—C71.462 (4)C8—H8A0.9700
N1—H1N10.86 (5)C8—H8B0.9700
N2—C11.445 (4)C9—H9A0.9600
C1—C21.398 (5)C9—H9B0.9600
C1—C61.428 (5)C9—H9C0.9600
C2—C31.378 (5)C11—C121.511 (5)
C2—H2A0.9300C11—H11A0.9700
C3—C41.409 (5)C11—H11B0.9700
C3—C101.477 (5)C12—H12A0.9600
C4—C51.364 (5)C12—H12B0.9600
C4—H4A0.9300C12—H12C0.9600
O1···O1i2.914 (5)O1···O1ii2.984 (5)
C10—O3—C11116.1 (3)C8—C7—H7B108.8
C6—N1—C7125.0 (3)H7A—C7—H7B107.7
C6—N1—H1N1118 (3)C9—C8—C7110.2 (3)
C7—N1—H1N1117 (3)C9—C8—H8A109.6
O2—N2—O1121.8 (3)C7—C8—H8A109.6
O2—N2—C1119.5 (3)C9—C8—H8B109.6
O1—N2—C1118.6 (3)C7—C8—H8B109.6
C2—C1—C6122.1 (3)H8A—C8—H8B108.1
C2—C1—N2116.1 (3)C8—C9—H9A109.5
C6—C1—N2121.8 (3)C8—C9—H9B109.5
C3—C2—C1120.6 (3)H9A—C9—H9B109.5
C3—C2—H2A119.7C8—C9—H9C109.5
C1—C2—H2A119.7H9A—C9—H9C109.5
C2—C3—C4118.4 (3)H9B—C9—H9C109.5
C2—C3—C10123.3 (3)O4—C10—O3123.5 (3)
C4—C3—C10118.2 (3)O4—C10—C3123.7 (3)
C5—C4—C3121.6 (3)O3—C10—C3112.8 (3)
C5—C4—H4A119.2O3—C11—C12110.8 (3)
C3—C4—H4A119.2O3—C11—H11A109.5
C4—C5—C6122.0 (3)C12—C11—H11A109.5
C4—C5—H5A119.0O3—C11—H11B109.5
C6—C5—H5A119.0C12—C11—H11B109.5
N1—C6—C5120.4 (3)H11A—C11—H11B108.1
N1—C6—C1124.4 (3)C11—C12—H12A109.5
C5—C6—C1115.2 (3)C11—C12—H12B109.5
N1—C7—C8113.8 (3)H12A—C12—H12B109.5
N1—C7—H7A108.8C11—C12—H12C109.5
C8—C7—H7A108.8H12A—C12—H12C109.5
N1—C7—H7B108.8H12B—C12—H12C109.5
O2—N2—C1—C25.7 (5)C4—C5—C6—C10.1 (5)
O1—N2—C1—C2174.0 (3)C2—C1—C6—N1178.9 (3)
O2—N2—C1—C6173.9 (3)N2—C1—C6—N10.5 (5)
O1—N2—C1—C66.5 (5)C2—C1—C6—C50.9 (5)
C6—C1—C2—C31.2 (5)N2—C1—C6—C5179.6 (3)
N2—C1—C2—C3179.2 (3)C6—N1—C7—C878.2 (4)
C1—C2—C3—C40.5 (5)N1—C7—C8—C9178.8 (3)
C1—C2—C3—C10178.7 (3)C11—O3—C10—O40.3 (5)
C2—C3—C4—C50.5 (5)C11—O3—C10—C3179.2 (3)
C10—C3—C4—C5177.8 (3)C2—C3—C10—O4175.7 (3)
C3—C4—C5—C60.9 (5)C4—C3—C10—O42.5 (5)
C7—N1—C6—C51.2 (5)C2—C3—C10—O34.8 (5)
C7—N1—C6—C1178.6 (3)C4—C3—C10—O3177.0 (3)
C4—C5—C6—N1180.0 (3)C10—O3—C11—C1285.5 (4)
Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N1···O10.85 (5)2.00 (6)2.633 (5)131 (5)
N1—H1N1···O1i0.85 (5)2.28 (5)2.998 (4)141 (5)
C2—H2A···O20.932.352.674 (4)100
Symmetry code: (i) x, y+1, z+1.

Experimental details

Crystal data
Chemical formulaC12H16N2O4
Mr252.27
Crystal system, space groupTriclinic, P1
Temperature (K)100
a, b, c (Å)4.4914 (4), 12.0828 (9), 12.8763 (9)
α, β, γ (°)62.494 (4), 81.055 (4), 83.494 (4)
V3)611.57 (8)
Z2
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.51 × 0.26 × 0.26
Data collection
DiffractometerBruker SMART APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.949, 0.974
No. of measured, independent and
observed [I > 2σ(I)] reflections
12286, 2372, 1946
Rint0.041
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.076, 0.252, 1.17
No. of reflections2372
No. of parameters169
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.47, 0.33

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

Selected interatomic distances (Å) top
O1···O1i2.914 (5)O1···O1ii2.984 (5)
Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N1···O10.85 (5)2.00 (6)2.633 (5)131 (5)
N1—H1N1···O1i0.85 (5)2.28 (5)2.998 (4)141 (5)
C2—H2A···O20.932.352.674 (4)100
Symmetry code: (i) x, y+1, z+1.
 

Footnotes

Additional correspondence author: e-mail: aisyah@usm.my.

Acknowledgements

This work was funded by the Malaysian Government and Universiti Sains Malaysia (USM) under the USM Research University Funding (1001/PFARMASI/815026). HKF and RK thank the Malaysian Government and Universiti sains Malaysia for the Science Fund grant No. 305/PFIZIK/613312. RK thanks Universiti Sains Malaysia for a postdoctoral research fellowship.

References

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Volume 64| Part 8| August 2008| Pages o1501-o1502
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