N-(5-Bromo­pyridin-2-yl)acetamide

Fun, H.-K.; Shahani, T.; Kumar, R.; Isloor, A.M.; Shivananda, K.N.

doi:10.1107/S1600536811027553

organic compounds

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ISSN: 2056-9890

Volume 67| Part 8| August 2011| Page o2043

doi:10.1107/S1600536811027553

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N-(5-Bromopyridin-2-yl)acetamide

Hoong-Kun Fun,^a ^*‡ Tara Shahani,^a Rajesha Kumar,^b Arun M. Isloor ^b and Kammasandra N. Shivananda ^c

^aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, ^bDepartment of Chemistry, National Institute of Technology–Karnataka, Surathkal, Mangalore 575 025, India, and ^cSchulich Faculty of Chemistry, Technion Israel Institute of Technology, Haifa 32000, Israel
^*Correspondence e-mail: hkfun@usm.my

(Received 25 June 2011; accepted 9 July 2011; online 16 July 2011)

The asymmetric unit of the title compound, C₇H₇BrN₂O, contains two molecules, in one of which the methyl H atoms are disorderd over two orientations in a 0.57 (3):0.43 (3) ratio. The dihedral angles between the pyridine rings and the acetamide groups are 7.27 (11) and 8.46 (11)°. In the crystal, molecules are linked by N—H⋯O and C—H⋯O hydrogen bonds generating bifurcated R₂¹(5) ring motifs, which in turn lead to [110] chains.

Related literature

For background to the acetylation of amines, see: Greene & Wuts (1999 ); Moore et al. (1940 ); Suyama & Gerwick (2006 ). For a related structure, see: Loureiro et al. (2008 ). For further synthetic information, see: Augustine et al. (2011 ); Sollogoub et al. (2002 ).

Experimental

Crystal data

C₇H₇BrN₂O
M_r = 215.06
Triclinic, $[P \overline 1]$
a = 4.0014 (3) Å
b = 8.7232 (6) Å
c = 23.0626 (18) Å
α = 82.127 (1)°
β = 86.897 (1)°
γ = 85.932 (1)°
V = 794.60 (10) Å³
Z = 4
Mo Kα radiation
μ = 5.11 mm⁻¹
T = 296 K
0.77 × 0.15 × 0.09 mm

Data collection

Bruker SMART APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009) T_min = 0.111, T_max = 0.665
13194 measured reflections
5134 independent reflections
3193 reflections with I > 2σ(I)
R_int = 0.025

Refinement

R[F² > 2σ(F²)] = 0.031
wR(F²) = 0.081
S = 1.00
5134 reflections
201 parameters
H-atom parameters constrained
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2A—H1NA⋯O1Bⁱ	0.85	2.16	3.001 (2)	169
N2B—H1NB⋯O1Aⁱⁱ	0.83	2.20	2.985 (2)	159
C7A—H7AA⋯O1Bⁱ	1.10	2.54	3.476 (3)	142
Symmetry codes: (i) x-1, y, z; (ii) x, y-1, z.

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; 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, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811027553/hb5933sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811027553/hb5933Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811027553/hb5933Isup3.cml

checkCIF report

Comment top

The acetylation of amines is an important method for protection (Greene & Wuts, 1999) of this basic functionality that is an important part of many natural products and medicinally important compounds such as sulphanilamide (Moore et al., 1940). In addition, certain natural products and medicinal compounds contain the acetamide functionality as part of the native compound or drug. Examples include epiquinamide, a compound isolated from a poison frog (Suyama et al., 2006) and Tylenol a common analgesic compound. Prompted by these, we synthesized the title compound, (I), and determined its crystal structure.

The asymmetric unit of (I) consists of two independent molecules of N-(5-bromopyridin-2-yl)acetamide (A & B) as shown in Fig. 1. In molecule A, the methyl hydrogen atoms are disordered over two sets of sites, with occupancy ratio of 0.57 (3):0.43 (3). The pyridine (N1A/C1A–C5A)/(N1B/C1B–C5B) rings are essentially planar, with maximum deviations of 0.006 (2) Å for atom C4A and 0.004 (2) Å for atom N1B, respectively. The dihedral angle between the pyridine (N1A/C1A–C5A)/(N1B/C1B–C5B) rings and acetamide (N2A/O1A/C5A–C7A)/ (N2B/O1B/C5B–C7B) groups are 7.27 (11)° and 8.46 (11)° respectively. The bond lengths and angles are normal and comparable to those in a related structure (Loureiro et al., 2008).

In the crystal (Fig. 2), the molecules are linked by intermolecular N2A—H1NA···O1B, N2B—H1NB···O1A and C7A—H7AA···O1B hydrogen bonds (Table 1) generating a bifurcated R¹₂(5) ring motif, resulting in supramolecular [1 1 0] chains.

Related literature top

For background to the acetylation of amines, see: Greene & Wuts (1999); Moore et al. (1940); Suyama et al. (2006). For a related structure, see: Loureiro et al. (2008). For further synthetic information, see: Augustine et al. (2011); Sollogoub et al. (2002).

Experimental top

(1E)-1-(5-Bromopyridin-2-yl)-N-hydroxyethanimine (2 g, 0.0093 mol) was taken in N,N dimethyl formamide (20 ml) at 25–26°C under a nitrogen atmosphere. Propylphosphonic anhydride (0.6 g, 0.00093 mol, 50% solution in ethylacetate) was added at the same temperature (Augustine et al., 2011). The reaction mixture was heated to 100°C for 5 hrs. The reaction mixture was cooled to 25–26°C and quenched onto ice-cold water. The precipitated white solid was filtered and dried under vacuum to get the desired product as a white solid which was then recrystallized from ethanol (Sollogoub et al., 2002) to yield colourless needles of (I). Yield 1.89 g (94.5%) Mp. 447–449 K.

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); 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, 2009).

Figures top

	Fig. 1. The molecular structure of the title compound, showing 20% probability displacement ellipsoids.
	Fig. 2. The crystal packing of the title compound, showing chains along the [110] direction. Only the major component is shown.

N-(5-Bromopyridin-2-yl)acetamide top

Crystal data top

C₇H₇BrN₂O	Z = 4
M_r = 215.06	F(000) = 424
Triclinic, P1	D_x = 1.798 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.0014 (3) Å	Cell parameters from 3316 reflections
b = 8.7232 (6) Å	θ = 2.8–30.5°
c = 23.0626 (18) Å	µ = 5.11 mm⁻¹
α = 82.127 (1)°	T = 296 K
β = 86.897 (1)°	Needle, colourless
γ = 85.932 (1)°	0.77 × 0.15 × 0.09 mm
V = 794.60 (10) Å³

Data collection top

Bruker SMART APEXII CCD diffractometer	5134 independent reflections
Radiation source: fine-focus sealed tube	3193 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.025
ϕ and ω scans	θ_max = 31.2°, θ_min = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −5→5
T_min = 0.111, T_max = 0.665	k = −12→12
13194 measured reflections	l = −33→33

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)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.081	H-atom parameters constrained
S = 1.00	w = 1/[σ²(F_o²) + (0.036P)² + 0.0264P] where P = (F_o² + 2F_c²)/3
5134 reflections	(Δ/σ)_max = 0.006
201 parameters	Δρ_max = 0.35 e Å⁻³
0 restraints	Δρ_min = −0.25 e Å⁻³

Crystal data top

C₇H₇BrN₂O	γ = 85.932 (1)°
M_r = 215.06	V = 794.60 (10) Å³
Triclinic, P1	Z = 4
a = 4.0014 (3) Å	Mo Kα radiation
b = 8.7232 (6) Å	µ = 5.11 mm⁻¹
c = 23.0626 (18) Å	T = 296 K
α = 82.127 (1)°	0.77 × 0.15 × 0.09 mm
β = 86.897 (1)°

Data collection top

Bruker SMART APEXII CCD diffractometer	5134 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2009)	3193 reflections with I > 2σ(I)
T_min = 0.111, T_max = 0.665	R_int = 0.025
13194 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.031	0 restraints
wR(F²) = 0.081	H-atom parameters constrained
S = 1.00	Δρ_max = 0.35 e Å⁻³
5134 reflections	Δρ_min = −0.25 e Å⁻³
201 parameters

Special details top

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	Occ. (<1)
Br1A	0.84865 (6)	0.73249 (2)	0.465121 (9)	0.05565 (9)
O1A	0.4679 (4)	0.97838 (16)	0.73640 (6)	0.0613 (5)
N1A	0.4235 (5)	0.63040 (18)	0.63081 (7)	0.0492 (4)
N2A	0.3137 (4)	0.75247 (17)	0.71180 (6)	0.0433 (4)
H1NA	0.2221	0.6674	0.7226	0.052*
C1A	0.5431 (6)	0.6264 (2)	0.57599 (9)	0.0509 (5)
H1AA	0.5303	0.5356	0.5595	0.061*
C2A	0.6845 (5)	0.7499 (2)	0.54257 (8)	0.0433 (4)
C3A	0.7046 (6)	0.8840 (2)	0.56632 (9)	0.0517 (5)
H3AA	0.7967	0.9695	0.5444	0.062*
C4A	0.5868 (6)	0.8907 (2)	0.62322 (9)	0.0515 (5)
H4AA	0.6018	0.9801	0.6405	0.062*
C5A	0.4449 (5)	0.7612 (2)	0.65427 (8)	0.0397 (4)
C6A	0.3318 (5)	0.8566 (2)	0.74991 (8)	0.0427 (4)
C7A	0.1744 (6)	0.8125 (3)	0.80974 (9)	0.0568 (6)
H7AA	0.0849	0.6942	0.8167	0.085*	0.57 (3)
H7AB	−0.0154	0.9051	0.8188	0.085*	0.57 (3)
H7AC	0.3210	0.8117	0.8427	0.085*	0.57 (3)
H7AD	0.2003	0.8929	0.8334	0.085*	0.43 (3)
H7AE	0.2826	0.7172	0.8275	0.085*	0.43 (3)
H7AF	−0.0598	0.7992	0.8067	0.085*	0.43 (3)
Br1B	0.14559 (6)	0.24850 (3)	1.034407 (9)	0.05895 (9)
O1B	0.9318 (4)	0.47747 (16)	0.76218 (6)	0.0586 (4)
N1B	0.4457 (5)	0.13387 (19)	0.87208 (7)	0.0566 (5)
N2B	0.6803 (4)	0.25146 (17)	0.78696 (6)	0.0464 (4)
H1NB	0.6598	0.1634	0.7785	0.056*
C1B	0.3245 (7)	0.1341 (2)	0.92681 (10)	0.0594 (6)
H1BA	0.2365	0.0441	0.9461	0.071*
C2B	0.3226 (5)	0.2599 (2)	0.95615 (8)	0.0443 (5)
C3B	0.4515 (6)	0.3934 (2)	0.92795 (9)	0.0513 (5)
H3BA	0.4549	0.4804	0.9471	0.062*
C4B	0.5752 (6)	0.3965 (2)	0.87127 (9)	0.0506 (5)
H4BA	0.6621	0.4857	0.8511	0.061*
C5B	0.5681 (5)	0.2635 (2)	0.84446 (8)	0.0403 (4)
C6B	0.8508 (5)	0.3553 (2)	0.74883 (8)	0.0430 (4)
C7B	0.9337 (6)	0.3063 (2)	0.68947 (8)	0.0535 (5)
H7BA	1.0711	0.3804	0.6667	0.080*
H7BB	0.7302	0.3009	0.6698	0.080*
H7BC	1.0528	0.2062	0.6939	0.080*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1A	0.06525 (17)	0.05384 (14)	0.05063 (13)	−0.01839 (11)	0.01455 (10)	−0.01617 (9)
O1A	0.0935 (13)	0.0446 (8)	0.0504 (8)	−0.0284 (8)	0.0052 (8)	−0.0140 (6)
N1A	0.0661 (12)	0.0349 (8)	0.0487 (9)	−0.0178 (8)	0.0068 (8)	−0.0091 (7)
N2A	0.0546 (11)	0.0322 (8)	0.0439 (9)	−0.0118 (7)	0.0042 (8)	−0.0063 (6)
C1A	0.0665 (15)	0.0360 (9)	0.0532 (11)	−0.0158 (10)	0.0074 (10)	−0.0145 (8)
C2A	0.0470 (12)	0.0400 (10)	0.0445 (10)	−0.0104 (9)	0.0036 (9)	−0.0099 (8)
C3A	0.0658 (15)	0.0391 (10)	0.0520 (11)	−0.0220 (10)	0.0111 (10)	−0.0080 (8)
C4A	0.0726 (16)	0.0332 (9)	0.0519 (11)	−0.0193 (10)	0.0085 (10)	−0.0128 (8)
C5A	0.0407 (11)	0.0332 (9)	0.0463 (10)	−0.0064 (8)	−0.0009 (8)	−0.0074 (7)
C6A	0.0502 (12)	0.0378 (9)	0.0413 (9)	−0.0058 (9)	−0.0029 (8)	−0.0076 (7)
C7A	0.0728 (16)	0.0567 (12)	0.0427 (11)	−0.0150 (12)	0.0061 (10)	−0.0107 (9)
Br1B	0.06627 (17)	0.06192 (15)	0.05093 (13)	−0.02114 (12)	0.01604 (11)	−0.01425 (10)
O1B	0.0785 (11)	0.0464 (8)	0.0529 (8)	−0.0275 (8)	0.0091 (7)	−0.0069 (6)
N1B	0.0841 (14)	0.0414 (9)	0.0473 (9)	−0.0249 (9)	0.0121 (9)	−0.0120 (7)
N2B	0.0627 (12)	0.0340 (8)	0.0443 (9)	−0.0145 (8)	0.0051 (8)	−0.0087 (6)
C1B	0.0811 (17)	0.0427 (11)	0.0564 (12)	−0.0266 (11)	0.0164 (12)	−0.0103 (9)
C2B	0.0432 (12)	0.0468 (10)	0.0444 (10)	−0.0127 (9)	0.0056 (8)	−0.0088 (8)
C3B	0.0667 (15)	0.0384 (10)	0.0517 (11)	−0.0149 (10)	0.0071 (10)	−0.0141 (8)
C4B	0.0701 (15)	0.0328 (9)	0.0500 (11)	−0.0175 (9)	0.0070 (10)	−0.0063 (8)
C5B	0.0452 (12)	0.0333 (9)	0.0438 (10)	−0.0093 (8)	−0.0007 (8)	−0.0073 (7)
C6B	0.0466 (12)	0.0375 (9)	0.0448 (10)	−0.0068 (9)	−0.0016 (8)	−0.0031 (8)
C7B	0.0610 (15)	0.0532 (12)	0.0471 (11)	−0.0127 (11)	0.0065 (10)	−0.0081 (9)

Geometric parameters (Å, º) top

Br1A—C2A	1.8914 (18)	C7A—H7AF	0.9600
O1A—C6A	1.223 (2)	Br1B—C2B	1.8951 (18)
N1A—C1A	1.331 (3)	O1B—C6B	1.218 (2)
N1A—C5A	1.338 (2)	N1B—C1B	1.328 (3)
N2A—C6A	1.356 (2)	N1B—C5B	1.331 (2)
N2A—C5A	1.395 (2)	N2B—C6B	1.365 (2)
N2A—H1NA	0.8514	N2B—C5B	1.392 (2)
C1A—C2A	1.374 (3)	N2B—H1NB	0.8288
C1A—H1AA	0.9300	C1B—C2B	1.365 (3)
C2A—C3A	1.367 (3)	C1B—H1BA	0.9300
C3A—C4A	1.378 (3)	C2B—C3B	1.373 (3)
C3A—H3AA	0.9300	C3B—C4B	1.370 (3)
C4A—C5A	1.391 (3)	C3B—H3BA	0.9300
C4A—H4AA	0.9300	C4B—C5B	1.390 (3)
C6A—C7A	1.498 (3)	C4B—H4BA	0.9300
C7A—H7AA	1.1046	C6B—C7B	1.503 (3)
C7A—H7AB	1.1020	C7B—H7BA	0.9600
C7A—H7AC	0.9834	C7B—H7BB	0.9600
C7A—H7AD	0.9601	C7B—H7BC	0.9600
C7A—H7AE	0.9601

C1A—N1A—C5A	117.99 (17)	H7AD—C7A—H7AE	109.5
C6A—N2A—C5A	127.87 (16)	C6A—C7A—H7AF	109.7
C6A—N2A—H1NA	120.4	H7AA—C7A—H7AF	60.9
C5A—N2A—H1NA	111.7	H7AB—C7A—H7AF	59.5
N1A—C1A—C2A	123.21 (18)	H7AC—C7A—H7AF	134.3
N1A—C1A—H1AA	118.4	H7AD—C7A—H7AF	109.5
C2A—C1A—H1AA	118.4	H7AE—C7A—H7AF	109.5
C3A—C2A—C1A	118.88 (18)	C1B—N1B—C5B	118.10 (17)
C3A—C2A—Br1A	121.10 (14)	C6B—N2B—C5B	128.33 (16)
C1A—C2A—Br1A	120.01 (14)	C6B—N2B—H1NB	119.6
C2A—C3A—C4A	119.17 (18)	C5B—N2B—H1NB	111.5
C2A—C3A—H3AA	120.4	N1B—C1B—C2B	123.26 (19)
C4A—C3A—H3AA	120.4	N1B—C1B—H1BA	118.4
C3A—C4A—C5A	118.69 (17)	C2B—C1B—H1BA	118.4
C3A—C4A—H4AA	120.7	C1B—C2B—C3B	118.78 (18)
C5A—C4A—H4AA	120.7	C1B—C2B—Br1B	120.11 (15)
N1A—C5A—C4A	122.06 (18)	C3B—C2B—Br1B	121.12 (15)
N1A—C5A—N2A	113.20 (16)	C4B—C3B—C2B	119.06 (18)
C4A—C5A—N2A	124.74 (16)	C4B—C3B—H3BA	120.5
O1A—C6A—N2A	122.27 (17)	C2B—C3B—H3BA	120.5
O1A—C6A—C7A	122.17 (17)	C3B—C4B—C5B	118.65 (18)
N2A—C6A—C7A	115.57 (17)	C3B—C4B—H4BA	120.7
C6A—C7A—H7AA	113.6	C5B—C4B—H4BA	120.7
C6A—C7A—H7AB	108.3	N1B—C5B—C4B	122.15 (18)
H7AA—C7A—H7AB	115.1	N1B—C5B—N2B	113.26 (16)
C6A—C7A—H7AC	115.8	C4B—C5B—N2B	124.59 (17)
H7AA—C7A—H7AC	102.8	O1B—C6B—N2B	122.50 (17)
H7AB—C7A—H7AC	100.6	O1B—C6B—C7B	122.78 (17)
C6A—C7A—H7AD	109.4	N2B—C6B—C7B	114.71 (16)
H7AA—C7A—H7AD	136.6	C6B—C7B—H7BA	109.5
H7AB—C7A—H7AD	53.5	C6B—C7B—H7BB	109.5
H7AC—C7A—H7AD	51.1	H7BA—C7B—H7BB	109.5
C6A—C7A—H7AE	109.4	C6B—C7B—H7BC	109.5
H7AA—C7A—H7AE	50.3	H7BA—C7B—H7BC	109.5
H7AB—C7A—H7AE	142.2	H7BB—C7B—H7BC	109.5
H7AC—C7A—H7AE	59.4

C5A—N1A—C1A—C2A	−0.4 (4)	C5B—N1B—C1B—C2B	−0.7 (4)
N1A—C1A—C2A—C3A	0.0 (4)	N1B—C1B—C2B—C3B	0.1 (4)
N1A—C1A—C2A—Br1A	179.81 (18)	N1B—C1B—C2B—Br1B	−179.7 (2)
C1A—C2A—C3A—C4A	0.8 (4)	C1B—C2B—C3B—C4B	0.5 (4)
Br1A—C2A—C3A—C4A	−178.97 (18)	Br1B—C2B—C3B—C4B	−179.66 (18)
C2A—C3A—C4A—C5A	−1.2 (4)	C2B—C3B—C4B—C5B	−0.5 (4)
C1A—N1A—C5A—C4A	0.0 (3)	C1B—N1B—C5B—C4B	0.7 (4)
C1A—N1A—C5A—N2A	−179.75 (19)	C1B—N1B—C5B—N2B	−178.4 (2)
C3A—C4A—C5A—N1A	0.8 (3)	C3B—C4B—C5B—N1B	−0.1 (4)
C3A—C4A—C5A—N2A	−179.5 (2)	C3B—C4B—C5B—N2B	179.0 (2)
C6A—N2A—C5A—N1A	171.58 (19)	C6B—N2B—C5B—N1B	−172.3 (2)
C6A—N2A—C5A—C4A	−8.2 (3)	C6B—N2B—C5B—C4B	8.6 (4)
C5A—N2A—C6A—O1A	1.7 (3)	C5B—N2B—C6B—O1B	0.9 (3)
C5A—N2A—C6A—C7A	−178.2 (2)	C5B—N2B—C6B—C7B	−179.8 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2A—H1NA···O1Bⁱ	0.85	2.16	3.001 (2)	169
N2B—H1NB···O1Aⁱⁱ	0.83	2.20	2.985 (2)	159
C7A—H7AA···O1Bⁱ	1.10	2.54	3.476 (3)	142

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

Experimental details

Crystal data
Chemical formula	C₇H₇BrN₂O
M_r	215.06
Crystal system, space group	Triclinic, P1
Temperature (K)	296
a, b, c (Å)	4.0014 (3), 8.7232 (6), 23.0626 (18)
α, β, γ (°)	82.127 (1), 86.897 (1), 85.932 (1)
V (Å³)	794.60 (10)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	5.11
Crystal size (mm)	0.77 × 0.15 × 0.09

Data collection
Diffractometer	Bruker SMART APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2009)
T_min, T_max	0.111, 0.665
No. of measured, independent and observed [I > 2σ(I)] reflections	13194, 5134, 3193
R_int	0.025
(sin θ/λ)_max (Å⁻¹)	0.729

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.031, 0.081, 1.00
No. of reflections	5134
No. of parameters	201
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.35, −0.25

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2A—H1NA···O1Bⁱ	0.85	2.16	3.001 (2)	169
N2B—H1NB···O1Aⁱⁱ	0.83	2.20	2.985 (2)	159
C7A—H7AA···O1Bⁱ	1.10	2.54	3.476 (3)	142

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

Footnotes

‡Thomson Reuters ResearcherID: A-3561-2009.

Acknowledgements

HKF and TSH thank Universiti Sains Malaysia (USM) for the Research University Grant (1001/PFIZIK/811160). TSH also thanks USM for the award of a research fellowship. AMI thanks Professor Sandeep Sanchethi, Director, National Institute of Technology–Karnataka, India, for his encouragement, and also the Defence Research and Development Organization, Government of India, for financial support.

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