Ethyl 4-(tert-butyl­amino)-3-nitro­benzoate

Mohd. Maidin, S.M.; Abdul Rahim, A.S.; Osman, H.; Kia, R.; Fun, H.-K.

doi:10.1107/S160053680802206X

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 64| Part 8| August 2008| Pages o1550-o1551

doi:10.1107/S160053680802206X

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Ethyl 4-(tert-butylamino)-3-nitrobenzoate

Siti Marina Mohd. Maidin,^a Aisyah Saad Abdul Rahim,^a ‡ Hasnah Osman,^b Reza Kia ^c and Hoong-Kun Fun ^c ^*

^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 11 July 2008; accepted 15 July 2008; online 19 July 2008)

In the title compound, C₁₃H₁₈N₂O₄, intramolecular N—H⋯O, N—H⋯N and C—H⋯O (× 3) hydrogen bonds generate S(6) and S(5) ring motifs. There are two crystallographically independent molecules (A and B) in the asymmetric unit. The nitro group is coplanar with the benzene ring, with O—N—C—C torsion angles of −0.33 (13) and 0.93 (14)° in molecules A and B, respectively. In the crystal structure, neighbouring molecules are linked together by intermolecular C—H⋯O hydrogen bonds. In addition, the crystal structure is stabilized by π–π interactions with centroid–centroid distances ranging from 3.7853 (6) to 3.8625 (6) Å.

Related literature

For literature on hydrogen-bond motifs, see: Bernstein et al. (1995 ). For values of bond lengths, see: Allen et al. (1987 ). For related literature, see, for example: Göker et al. (1998 ); Anderson (2005 ); Kakei et al. (1993 ).

Experimental

Crystal data

C₁₃H₁₈N₂O₄
M_r = 266.29
Monoclinic, P 2₁ /c
a = 16.0471 (5) Å
b = 6.6417 (2) Å
c = 30.0180 (9) Å
β = 121.688 (2)°
V = 2722.37 (14) Å³
Z = 8
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 100.0 (1) K
0.51 × 0.43 × 0.17 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ) T_min = 0.879, T_max = 0.984
63326 measured reflections
8141 independent reflections
6368 reflections with I > 2σ(I)
R_int = 0.033

Refinement

R[F² > 2σ(F²)] = 0.046
wR(F²) = 0.133
S = 1.04
8141 reflections
351 parameters
H-atom parameters constrained
Δρ_max = 0.53 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Table 1
Selected centroid–centroid distances (Å)

Cg1 and Cg2 are the centroids of the C1A–C6A and C1B–C6B rings, respectively.

Cg1⋯Cg2ⁱ	3.7853 (6)
Cg1⋯Cg2ⁱⁱ	3.8625 (6)
Symmetry codes: (i) $[x, -y-{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (ii) $[x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ .

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2A—H2NA⋯O4A	0.86	1.93	2.6299 (15)	138
N2A—H2NA⋯N1A	0.86	2.54	2.9361 (15)	109
N2B—H2NB⋯O4B	0.87	1.95	2.6355 (15)	134
N2B—H2NB⋯N1B	0.87	2.58	2.9419 (15)	106
C1A—H1A⋯O3A	0.95	2.31	2.6522 (16)	100
C1B—H1B⋯O3B	0.95	2.31	2.6498 (16)	100
C4A—H4A⋯O3Bⁱⁱⁱ	0.95	2.50	3.4124 (17)	160
C4B—H4B⋯O3A^iv	0.95	2.42	3.2566 (18)	147
C5A—H5A⋯O1A	0.95	2.41	2.7326 (13)	100
C11A—H11A⋯O2B^v	0.98	2.55	3.4714 (17)	157
C11B—H11F⋯O2Aⁱⁱ	0.98	2.52	3.4446 (17)	158
C13B—H13D⋯O2A^vi	0.98	2.60	3.5071 (17)	154
Symmetry codes: (ii) $[x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (iii) -x+2, -y+1, -z+1; (iv) -x+1, -y+1, -z+1; (v) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (vi) $[x, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]$ .

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

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680802206X/at2594sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053680802206X/at2594Isup2.hkl

checkCIF report

Comment top

As a part of our ongoing studies on new nitro benzoic acid derivatives, we have synthesized the title compound (I) employing a modified protocol of previous procedure (Göker et al., 1998). The nitro benzoic acid intermediates are a convenient starting material for the synthesis of heterocycles targeting important biological processes, e.g. antifungal (Fluconazole) (Anderson, 2005) and proton pump inhibitor (Omeprazole) (Kakei et al., 1993). The crystal structure of the tert-butylamino functionalized nitro benzoic acid (I) has been determined, and herein, we present a full report on its crystal structure.

In the title compound (I) (Fig. 1), intramolecular N—H···O (x 2), N—H···N (x 2), and C—H···O (x 3) hydrogen bonds (Table 2) generate S(6) and S(5) ring motifs, respectively (Bernstein et al., 1995). There are two crystallographically independent molecules, A and B in the asymmetric unit of the title compound. The nitro group is coplanar with the benzene ring with torsion angle of -0.33 (13) and 0.93 (14)° in the molecule A and B, respectively. In the crystal structure neighbouring molecules are linked together by intermolecular C—H···O hydrogen bonds (Table 1). In the crystal packing (Table 2 & Fig. 2), molecules are stacked down the b axis, being consolidated by π–π interactions with centroid to centroid distances ranging from 3.7853 (6) – 3.8625 (6) Å.

The crystal structure is stabilized by intramolecular N—H···O (x 2), N—H···N (x 2), C—H···O (x 3), and intermolecular C—H···O (x 5) hydrogen bonds and π–π interactions.

Related literature top

For related literature on hydrogen-bond motifs, see: Bernstein et al. (1995). For values of bond lengths, see: Allen et al. (1987). For related literature, see, for example: Göker et al. (1998); Anderson (2005); Kakei et al. (1993).

Experimental top

Ethyl 4-fluoro-3-nitrobenzoate (200 mg, 0.93 mmol) was dissolved in dry dichloromethane (10 ml). N, N-diisopropylethylamine (DIPEA) (0.20 ml, 1.12 mmol) was added to the stirred mixture. Then, tert-butylamine (0.11 ml, 1.03 mmol) was added dropwise using syringe and stirred at room temperature under N₂ overnight. After completion of the reaction, the mixture was washed with 10% NaCO₃ (10 ml). The aqueous layer was washed with dichloromethane (3 x 15 ml). The organic layers were collected and dried over MgSO₄(anhydrous). The solvent was removed under reduced pressure to yield the crude product. Recrystallisation with hot hexane revealed the title compound (I) as bright yellow crystals.

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

	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.
	Fig. 2. The crystal packing of (I), showing stacking arrangement viewed down the b-axis. Intramolecular and intermolecular interactions are drawn as dashed lines.

Ethyl 4-(tert-butylamino)-3-nitrobenzoate top

Crystal data top

C₁₃H₁₈N₂O₄	F(000) = 1136
M_r = 266.29	D_x = 1.299 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 9969 reflections
a = 16.0471 (5) Å	θ = 2.5–30.1°
b = 6.6417 (2) Å	µ = 0.10 mm⁻¹
c = 30.0180 (9) Å	T = 100 K
β = 121.688 (2)°	Plate, yellow
V = 2722.37 (14) Å³	0.51 × 0.43 × 0.17 mm
Z = 8

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	8141 independent reflections
Radiation source: fine-focus sealed tube	6368 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.033
ϕ and ω scans	θ_max = 30.3°, θ_min = 1.5°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −21→22
T_min = 0.879, T_max = 0.984	k = −9→9
63326 measured reflections	l = −41→42

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)] = 0.047	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.133	H-atom parameters constrained
S = 1.04	w = 1/[σ²(F_o²) + (0.0652P)² + 0.787P] where P = (F_o² + 2F_c²)/3
8141 reflections	(Δ/σ)_max = 0.001
351 parameters	Δρ_max = 0.53 e Å⁻³
0 restraints	Δρ_min = −0.24 e Å⁻³

Crystal data top

C₁₃H₁₈N₂O₄	V = 2722.37 (14) Å³
M_r = 266.29	Z = 8
Monoclinic, P2₁/c	Mo Kα radiation
a = 16.0471 (5) Å	µ = 0.10 mm⁻¹
b = 6.6417 (2) Å	T = 100 K
c = 30.0180 (9) Å	0.51 × 0.43 × 0.17 mm
β = 121.688 (2)°

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	8141 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2005)	6368 reflections with I > 2σ(I)
T_min = 0.879, T_max = 0.984	R_int = 0.033
63326 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.047	0 restraints
wR(F²) = 0.133	H-atom parameters constrained
S = 1.04	Δρ_max = 0.53 e Å⁻³
8141 reflections	Δρ_min = −0.24 e Å⁻³
351 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

	x	y	z	U_iso*/U_eq
O1A	1.01188 (6)	0.50707 (13)	0.90700 (3)	0.02027 (18)
O2A	0.87073 (6)	0.53054 (14)	0.90534 (3)	0.02371 (19)
O3A	0.57249 (6)	0.54152 (13)	0.73478 (3)	0.02243 (18)
O4A	0.56803 (6)	0.54680 (13)	0.66152 (3)	0.02250 (18)
N1A	0.61441 (6)	0.54228 (13)	0.71013 (4)	0.01589 (18)
N2A	0.73120 (6)	0.54415 (13)	0.66080 (3)	0.01583 (18)
H2NA	0.6682	0.5497	0.6444	0.019*
C1A	0.76647 (7)	0.53258 (15)	0.79329 (4)	0.0143 (2)
H1A	0.7281	0.5335	0.8089	0.017*
C2A	0.72036 (7)	0.53705 (15)	0.73898 (4)	0.01349 (19)
C3A	0.77441 (7)	0.53716 (14)	0.71324 (4)	0.01347 (19)
C4A	0.87825 (7)	0.52932 (15)	0.74731 (4)	0.0151 (2)
H4A	0.9180	0.5271	0.7325	0.018*
C5A	0.92253 (7)	0.52490 (15)	0.80055 (4)	0.0149 (2)
H5A	0.9920	0.5204	0.8217	0.018*
C6A	0.86747 (7)	0.52682 (15)	0.82473 (4)	0.0142 (2)
C7A	0.91408 (8)	0.52224 (16)	0.88226 (4)	0.0159 (2)
C8A	1.06291 (8)	0.5008 (2)	0.96363 (4)	0.0252 (3)
H8A	1.0412	0.3828	0.9751	0.030*
H8B	1.0489	0.6242	0.9771	0.030*
C9A	1.17025 (9)	0.4861 (2)	0.98412 (5)	0.0347 (3)
H9A	1.2069	0.4877	1.0225	0.052*
H9B	1.1904	0.6006	0.9713	0.052*
H9C	1.1837	0.3603	0.9720	0.052*
C10A	0.77667 (8)	0.54745 (16)	0.62878 (4)	0.0163 (2)
C11A	0.83246 (8)	0.35165 (17)	0.63510 (4)	0.0203 (2)
H11A	0.7877	0.2370	0.6254	0.030*
H11B	0.8861	0.3373	0.6716	0.030*
H11C	0.8593	0.3555	0.6124	0.030*
C12A	0.68959 (9)	0.56150 (19)	0.57218 (4)	0.0233 (2)
H12A	0.6458	0.4465	0.5647	0.035*
H12B	0.7136	0.5600	0.5481	0.035*
H12C	0.6537	0.6869	0.5676	0.035*
C13A	0.84047 (8)	0.73502 (17)	0.64034 (4)	0.0195 (2)
H13A	0.8927	0.7359	0.6774	0.029*
H13B	0.8000	0.8560	0.6324	0.029*
H13C	0.8695	0.7331	0.6186	0.029*
O1B	0.49200 (5)	0.43211 (13)	0.10402 (3)	0.02139 (18)
O2B	0.63293 (6)	0.45058 (13)	0.10484 (3)	0.02286 (18)
O3B	0.93204 (6)	0.47400 (13)	0.27341 (3)	0.02111 (18)
O4B	0.93898 (6)	0.47557 (13)	0.34743 (3)	0.02151 (18)
N1B	0.89147 (6)	0.47252 (13)	0.29872 (4)	0.01529 (18)
N2B	0.77682 (6)	0.47199 (14)	0.34950 (3)	0.01565 (18)
H2NB	0.8407	0.4767	0.3671	0.019*
C1B	0.73817 (7)	0.46115 (15)	0.21633 (4)	0.01401 (19)
H1B	0.7757	0.4608	0.2002	0.017*
C2B	0.78566 (7)	0.46722 (15)	0.27069 (4)	0.01293 (19)
C3B	0.73273 (7)	0.46737 (15)	0.29702 (4)	0.01340 (19)
C4B	0.62889 (8)	0.46322 (16)	0.26366 (4)	0.0157 (2)
H4B	0.5900	0.4645	0.2790	0.019*
C5B	0.58317 (7)	0.45740 (15)	0.21029 (4)	0.0154 (2)
H5B	0.5137	0.4545	0.1895	0.019*
C6B	0.63721 (7)	0.45564 (15)	0.18553 (4)	0.01401 (19)
C7B	0.58976 (8)	0.44669 (16)	0.12800 (4)	0.0168 (2)
C8B	0.43816 (8)	0.4179 (2)	0.04737 (4)	0.0260 (3)
H8C	0.3751	0.3484	0.0350	0.031*
H8D	0.4762	0.3370	0.0365	0.031*
C9B	0.41883 (9)	0.6226 (2)	0.02271 (5)	0.0302 (3)
H9D	0.3804	0.6089	−0.0155	0.045*
H9E	0.4812	0.6888	0.0335	0.045*
H9F	0.3822	0.7038	0.0340	0.045*
C10B	0.73206 (8)	0.46992 (16)	0.38189 (4)	0.0172 (2)
C11B	0.67381 (8)	0.27595 (17)	0.37340 (4)	0.0217 (2)
H11D	0.6189	0.2698	0.3370	0.032*
H11E	0.6487	0.2747	0.3969	0.032*
H11F	0.7166	0.1593	0.3809	0.032*
C12B	0.81999 (9)	0.47351 (19)	0.43837 (4)	0.0246 (2)
H12D	0.8582	0.5964	0.4441	0.037*
H12E	0.8613	0.3555	0.4445	0.037*
H12F	0.7966	0.4710	0.4627	0.037*
C13B	0.66997 (8)	0.65807 (18)	0.37269 (5)	0.0222 (2)
H13D	0.7108	0.7784	0.3806	0.033*
H13E	0.6433	0.6541	0.3955	0.033*
H13F	0.6160	0.6623	0.3360	0.033*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1A	0.0132 (3)	0.0327 (5)	0.0134 (4)	0.0004 (3)	0.0059 (3)	−0.0014 (3)
O2A	0.0181 (4)	0.0365 (5)	0.0190 (4)	0.0000 (3)	0.0114 (3)	−0.0013 (3)
O3A	0.0154 (4)	0.0298 (5)	0.0260 (4)	0.0006 (3)	0.0135 (3)	0.0003 (3)
O4A	0.0136 (4)	0.0309 (5)	0.0186 (4)	0.0002 (3)	0.0055 (3)	−0.0002 (3)
N1A	0.0126 (4)	0.0142 (4)	0.0205 (4)	−0.0004 (3)	0.0084 (3)	−0.0004 (3)
N2A	0.0120 (4)	0.0192 (4)	0.0151 (4)	0.0004 (3)	0.0062 (3)	0.0003 (3)
C1A	0.0149 (5)	0.0111 (4)	0.0189 (5)	−0.0006 (3)	0.0104 (4)	−0.0004 (4)
C2A	0.0102 (4)	0.0119 (5)	0.0175 (5)	0.0002 (3)	0.0068 (4)	0.0002 (4)
C3A	0.0135 (4)	0.0099 (4)	0.0168 (5)	−0.0006 (3)	0.0078 (4)	−0.0003 (3)
C4A	0.0127 (4)	0.0155 (5)	0.0182 (5)	0.0003 (4)	0.0088 (4)	0.0005 (4)
C5A	0.0124 (4)	0.0145 (5)	0.0175 (5)	0.0003 (4)	0.0076 (4)	0.0006 (4)
C6A	0.0147 (5)	0.0131 (5)	0.0148 (5)	−0.0004 (4)	0.0077 (4)	−0.0005 (4)
C7A	0.0140 (5)	0.0160 (5)	0.0170 (5)	−0.0009 (4)	0.0075 (4)	−0.0013 (4)
C8A	0.0188 (5)	0.0421 (7)	0.0122 (5)	0.0004 (5)	0.0065 (4)	−0.0021 (5)
C9A	0.0184 (6)	0.0630 (10)	0.0180 (6)	0.0030 (6)	0.0063 (5)	−0.0027 (6)
C10A	0.0161 (5)	0.0183 (5)	0.0154 (5)	−0.0005 (4)	0.0088 (4)	0.0001 (4)
C11A	0.0208 (5)	0.0181 (5)	0.0240 (5)	−0.0002 (4)	0.0131 (4)	−0.0028 (4)
C12A	0.0212 (5)	0.0303 (6)	0.0157 (5)	−0.0009 (5)	0.0078 (4)	−0.0005 (4)
C13A	0.0205 (5)	0.0190 (5)	0.0203 (5)	−0.0011 (4)	0.0116 (4)	0.0018 (4)
O1B	0.0133 (4)	0.0343 (5)	0.0138 (4)	−0.0022 (3)	0.0053 (3)	0.0013 (3)
O2B	0.0181 (4)	0.0339 (5)	0.0178 (4)	0.0012 (3)	0.0102 (3)	−0.0004 (3)
O3B	0.0150 (4)	0.0280 (4)	0.0238 (4)	0.0003 (3)	0.0127 (3)	0.0009 (3)
O4B	0.0136 (4)	0.0302 (5)	0.0164 (4)	0.0002 (3)	0.0049 (3)	0.0004 (3)
N1B	0.0135 (4)	0.0134 (4)	0.0186 (4)	0.0001 (3)	0.0081 (3)	0.0002 (3)
N2B	0.0129 (4)	0.0195 (4)	0.0143 (4)	0.0001 (3)	0.0070 (3)	0.0001 (3)
C1B	0.0144 (4)	0.0125 (5)	0.0168 (5)	0.0004 (3)	0.0093 (4)	0.0006 (4)
C2B	0.0108 (4)	0.0113 (4)	0.0166 (5)	0.0003 (3)	0.0072 (4)	0.0007 (3)
C3B	0.0147 (5)	0.0101 (4)	0.0151 (5)	0.0004 (3)	0.0077 (4)	0.0010 (3)
C4B	0.0137 (4)	0.0173 (5)	0.0185 (5)	0.0004 (4)	0.0100 (4)	0.0005 (4)
C5B	0.0121 (4)	0.0151 (5)	0.0185 (5)	0.0000 (4)	0.0076 (4)	0.0007 (4)
C6B	0.0135 (4)	0.0133 (5)	0.0148 (5)	0.0000 (3)	0.0071 (4)	0.0009 (3)
C7B	0.0152 (5)	0.0170 (5)	0.0163 (5)	0.0001 (4)	0.0070 (4)	0.0007 (4)
C8B	0.0176 (5)	0.0410 (7)	0.0148 (5)	−0.0037 (5)	0.0055 (4)	−0.0017 (5)
C9B	0.0236 (6)	0.0469 (8)	0.0197 (6)	0.0022 (5)	0.0111 (5)	0.0074 (5)
C10B	0.0194 (5)	0.0187 (5)	0.0158 (5)	0.0009 (4)	0.0107 (4)	0.0007 (4)
C11B	0.0255 (6)	0.0209 (5)	0.0226 (5)	−0.0013 (4)	0.0154 (5)	0.0024 (4)
C12B	0.0265 (6)	0.0306 (6)	0.0152 (5)	0.0009 (5)	0.0099 (5)	0.0008 (4)
C13B	0.0242 (5)	0.0205 (5)	0.0251 (6)	0.0019 (4)	0.0151 (5)	−0.0022 (4)

Geometric parameters (Å, º) top

O1A—C7A	1.3418 (13)	O1B—C7B	1.3424 (13)
O1A—C8A	1.4489 (13)	O1B—C8B	1.4503 (13)
O2A—C7A	1.2136 (13)	O2B—C7B	1.2125 (13)
O3A—N1A	1.2340 (12)	O3B—N1B	1.2332 (12)
O4A—N1A	1.2424 (12)	O4B—N1B	1.2443 (12)
N1A—C2A	1.4474 (13)	N1B—C2B	1.4462 (13)
N2A—C3A	1.3470 (13)	N2B—C3B	1.3463 (13)
N2A—C10A	1.4810 (13)	N2B—C10B	1.4816 (13)
N2A—H2NA	0.8617	N2B—H2NB	0.8733
C1A—C6A	1.3827 (14)	C1B—C6B	1.3809 (14)
C1A—C2A	1.3925 (14)	C1B—C2B	1.3924 (14)
C1A—H1A	0.9500	C1B—H1B	0.9500
C2A—C3A	1.4328 (14)	C2B—C3B	1.4321 (14)
C3A—C4A	1.4265 (14)	C3B—C4B	1.4238 (14)
C4A—C5A	1.3663 (14)	C4B—C5B	1.3683 (14)
C4A—H4A	0.9500	C4B—H4B	0.9500
C5A—C6A	1.4076 (14)	C5B—C6B	1.4076 (14)
C5A—H5A	0.9500	C5B—H5B	0.9500
C6A—C7A	1.4784 (14)	C6B—C7B	1.4778 (14)
C8A—C9A	1.4973 (17)	C8B—C9B	1.5003 (19)
C8A—H8A	0.9900	C8B—H8C	0.9900
C8A—H8B	0.9900	C8B—H8D	0.9900
C9A—H9A	0.9800	C9B—H9D	0.9800
C9A—H9B	0.9800	C9B—H9E	0.9800
C9A—H9C	0.9800	C9B—H9F	0.9800
C10A—C13A	1.5320 (15)	C10B—C13B	1.5302 (15)
C10A—C11A	1.5331 (15)	C10B—C11B	1.5323 (15)
C10A—C12A	1.5343 (15)	C10B—C12B	1.5338 (15)
C11A—H11A	0.9800	C11B—H11D	0.9800
C11A—H11B	0.9800	C11B—H11E	0.9800
C11A—H11C	0.9800	C11B—H11F	0.9800
C12A—H12A	0.9800	C12B—H12D	0.9800
C12A—H12B	0.9800	C12B—H12E	0.9800
C12A—H12C	0.9800	C12B—H12F	0.9800
C13A—H13A	0.9800	C13B—H13D	0.9800
C13A—H13B	0.9800	C13B—H13E	0.9800
C13A—H13C	0.9800	C13B—H13F	0.9800

Cg1···Cg2ⁱ	3.7853 (6)	Cg1···Cg2ⁱⁱ	3.8625 (6)

C7A—O1A—C8A	115.30 (9)	C7B—O1B—C8B	116.24 (9)
O3A—N1A—O4A	121.71 (9)	O3B—N1B—O4B	121.87 (9)
O3A—N1A—C2A	118.70 (9)	O3B—N1B—C2B	118.70 (9)
O4A—N1A—C2A	119.59 (9)	O4B—N1B—C2B	119.43 (9)
C3A—N2A—C10A	129.22 (9)	C3B—N2B—C10B	129.04 (9)
C3A—N2A—H2NA	113.4	C3B—N2B—H2NB	115.9
C10A—N2A—H2NA	117.3	C10B—N2B—H2NB	115.0
C6A—C1A—C2A	120.74 (9)	C6B—C1B—C2B	120.85 (9)
C6A—C1A—H1A	119.6	C6B—C1B—H1B	119.6
C2A—C1A—H1A	119.6	C2B—C1B—H1B	119.6
C1A—C2A—C3A	122.10 (9)	C1B—C2B—C3B	121.91 (9)
C1A—C2A—N1A	115.83 (9)	C1B—C2B—N1B	115.79 (9)
C3A—C2A—N1A	122.07 (9)	C3B—C2B—N1B	122.30 (9)
N2A—C3A—C4A	121.97 (9)	N2B—C3B—C4B	121.65 (9)
N2A—C3A—C2A	122.98 (9)	N2B—C3B—C2B	123.11 (9)
C4A—C3A—C2A	115.05 (9)	C4B—C3B—C2B	115.23 (9)
C5A—C4A—C3A	122.23 (10)	C5B—C4B—C3B	122.25 (9)
C5A—C4A—H4A	118.9	C5B—C4B—H4B	118.9
C3A—C4A—H4A	118.9	C3B—C4B—H4B	118.9
C4A—C5A—C6A	121.42 (9)	C4B—C5B—C6B	121.22 (9)
C4A—C5A—H5A	119.3	C4B—C5B—H5B	119.4
C6A—C5A—H5A	119.3	C6B—C5B—H5B	119.4
C1A—C6A—C5A	118.45 (9)	C1B—C6B—C5B	118.54 (9)
C1A—C6A—C7A	119.36 (9)	C1B—C6B—C7B	119.12 (9)
C5A—C6A—C7A	122.19 (9)	C5B—C6B—C7B	122.34 (9)
O2A—C7A—O1A	122.82 (10)	O2B—C7B—O1B	123.56 (10)
O2A—C7A—C6A	125.16 (10)	O2B—C7B—C6B	124.77 (10)
O1A—C7A—C6A	112.03 (9)	O1B—C7B—C6B	111.67 (9)
O1A—C8A—C9A	107.65 (9)	O1B—C8B—C9B	111.18 (11)
O1A—C8A—H8A	110.2	O1B—C8B—H8C	109.4
C9A—C8A—H8A	110.2	C9B—C8B—H8C	109.4
O1A—C8A—H8B	110.2	O1B—C8B—H8D	109.4
C9A—C8A—H8B	110.2	C9B—C8B—H8D	109.4
H8A—C8A—H8B	108.5	H8C—C8B—H8D	108.0
C8A—C9A—H9A	109.5	C8B—C9B—H9D	109.5
C8A—C9A—H9B	109.5	C8B—C9B—H9E	109.5
H9A—C9A—H9B	109.5	H9D—C9B—H9E	109.5
C8A—C9A—H9C	109.5	C8B—C9B—H9F	109.5
H9A—C9A—H9C	109.5	H9D—C9B—H9F	109.5
H9B—C9A—H9C	109.5	H9E—C9B—H9F	109.5
N2A—C10A—C13A	111.31 (9)	N2B—C10B—C13B	111.59 (9)
N2A—C10A—C11A	111.21 (9)	N2B—C10B—C11B	111.24 (9)
C13A—C10A—C11A	112.61 (9)	C13B—C10B—C11B	111.97 (9)
N2A—C10A—C12A	104.30 (8)	N2B—C10B—C12B	104.10 (9)
C13A—C10A—C12A	108.24 (9)	C13B—C10B—C12B	108.70 (9)
C11A—C10A—C12A	108.76 (9)	C11B—C10B—C12B	108.88 (9)
C10A—C11A—H11A	109.5	C10B—C11B—H11D	109.5
C10A—C11A—H11B	109.5	C10B—C11B—H11E	109.5
H11A—C11A—H11B	109.5	H11D—C11B—H11E	109.5
C10A—C11A—H11C	109.5	C10B—C11B—H11F	109.5
H11A—C11A—H11C	109.5	H11D—C11B—H11F	109.5
H11B—C11A—H11C	109.5	H11E—C11B—H11F	109.5
C10A—C12A—H12A	109.5	C10B—C12B—H12D	109.5
C10A—C12A—H12B	109.5	C10B—C12B—H12E	109.5
H12A—C12A—H12B	109.5	H12D—C12B—H12E	109.5
C10A—C12A—H12C	109.5	C10B—C12B—H12F	109.5
H12A—C12A—H12C	109.5	H12D—C12B—H12F	109.5
H12B—C12A—H12C	109.5	H12E—C12B—H12F	109.5
C10A—C13A—H13A	109.5	C10B—C13B—H13D	109.5
C10A—C13A—H13B	109.5	C10B—C13B—H13E	109.5
H13A—C13A—H13B	109.5	H13D—C13B—H13E	109.5
C10A—C13A—H13C	109.5	C10B—C13B—H13F	109.5
H13A—C13A—H13C	109.5	H13D—C13B—H13F	109.5
H13B—C13A—H13C	109.5	H13E—C13B—H13F	109.5

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2A—H2NA···O4A	0.86	1.93	2.6299 (15)	138
N2A—H2NA···N1A	0.86	2.54	2.9361 (15)	109
N2B—H2NB···O4B	0.87	1.95	2.6355 (15)	134
N2B—H2NB···N1B	0.87	2.58	2.9419 (15)	106
C1A—H1A···O3A	0.95	2.31	2.6522 (16)	100
C1B—H1B···O3B	0.95	2.31	2.6498 (16)	100
C4A—H4A···O3Bⁱⁱⁱ	0.95	2.50	3.4124 (17)	160
C4B—H4B···O3A^iv	0.95	2.42	3.2566 (18)	147
C5A—H5A···O1A	0.95	2.41	2.7326 (13)	100
C11A—H11A···O2B^v	0.98	2.55	3.4714 (17)	157
C11B—H11F···O2Aⁱⁱ	0.98	2.52	3.4446 (17)	158
C13B—H13D···O2A^vi	0.98	2.60	3.5071 (17)	154

Symmetry codes: (ii) x, −y+1/2, z−1/2; (iii) −x+2, −y+1, −z+1; (iv) −x+1, −y+1, −z+1; (v) x, −y+1/2, z+1/2; (vi) x, −y+3/2, z−1/2.

Experimental details

Crystal data
Chemical formula	C₁₃H₁₈N₂O₄
M_r	266.29
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	100
a, b, c (Å)	16.0471 (5), 6.6417 (2), 30.0180 (9)
β (°)	121.688 (2)
V (Å³)	2722.37 (14)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.51 × 0.43 × 0.17

Data collection
Diffractometer	Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.879, 0.984
No. of measured, independent and observed [I > 2σ(I)] reflections	63326, 8141, 6368
R_int	0.033
(sin θ/λ)_max (Å⁻¹)	0.709

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.047, 0.133, 1.04
No. of reflections	8141
No. of parameters	351
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.53, −0.24

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

Selected interatomic distances (Å) top

Cg1···Cg2ⁱ

3.7853 (6)

Cg1···Cg2ⁱⁱ

3.8625 (6)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2A—H2NA···O4A	0.8600	1.9300	2.6299 (15)	138.00
N2A—H2NA···N1A	0.8600	2.5400	2.9361 (15)	109.00
N2B—H2NB···O4B	0.8700	1.9500	2.6355 (15)	134.00
N2B—H2NB···N1B	0.8700	2.5800	2.9419 (15)	106.00
C1A—H1A···O3A	0.9500	2.3100	2.6522 (16)	100.00
C1B—H1B···O3B	0.9500	2.3100	2.6498 (16)	100.00
C4A—H4A···O3Bⁱⁱⁱ	0.9500	2.5000	3.4124 (17)	160.00
C4B—H4B···O3A^iv	0.9500	2.4200	3.2566 (18)	147.00
C5A—H5A···O1A	0.9500	2.4100	2.7326 (13)	100.00
C11A—H11A···O2B^v	0.9800	2.5500	3.4714 (17)	157.00
C11B—H11F···O2Aⁱⁱ	0.9800	2.5200	3.4446 (17)	158.00
C13B—H13D···O2A^vi	0.9800	2.6000	3.5071 (17)	154.00

Symmetry codes: (ii) x, −y+1/2, z−1/2; (iii) −x+2, −y+1, −z+1; (iv) −x+1, −y+1, −z+1; (v) x, −y+1/2, z+1/2; (vi) x, −y+3/2, z−1/2.

Footnotes

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

Acknowledgements

We are grateful to the Malaysian Government and Universiti Sains Malaysia (USM) for financial support given 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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