3,4-Dimethyl­pyrano[2,3-c]pyrazol-6(2H)-one

Shahid, B.; Zia-ur-Rehman, M.; Nadeem Arshad, M.; Nazir, R.; Şahin, E.

doi:10.1107/S1600536812012779

organic compounds

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ISSN: 2056-9890

Volume 68| Part 4| April 2012| Page o1217

doi:10.1107/S1600536812012779

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3,4-Dimethylpyrano[2,3-c]pyrazol-6(2H)-one

Bilal Shahid,^a Muhammad Zia-ur-Rehman,^b ^* Muhammad Nadeem Arshad,^c Rabia Nazir ^b and Ertan Şahin ^d

^aDepartment of Chemistry, GC University, Lahore 54000, Pakistan, ^bApplied Chemistry Research Centre, Pakistan Council of Scientific & Industrial Research Laboratories Complex, Lahore 54600, Pakistan, ^cDepartment of Chemistry, University of Gujrat (H. H. Campus), Gujrat 57000, Pakistan, and ^dDepartment of Chemistry, Faculty of Science, Atatürk University, 25240 Erzurum, Turkey
^*Correspondence e-mail: rehman_pcsir@hotmail.com

(Received 22 March 2012; accepted 23 March 2012; online 28 March 2012)

The asymmetric unit of the title compound, C₈H₈N₂O₂, comprises two independent molecules in both of which, all non-H atoms lie in a common plane (r.m.s. deviation = 0.014 and 0.017 Å). In the crystal, N—H⋯O hydrogen bonds connect the molecules into zigzag chains running along [10-1]. Weak C—H⋯O interactions connect the chains into an infinite network.

Related literature

For related structures, see: Ahmad et al. (2011 ); Ramsay & Steel (1985 ).

Experimental

Crystal data

C₈H₈N₂O₂
M_r = 164.16
Monoclinic, P 2₁ /n
a = 13.6219 (3) Å
b = 6.8766 (2) Å
c = 16.2369 (4) Å
β = 96.091 (2)°
V = 1512.36 (7) Å³
Z = 8
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 296 K
0.30 × 0.18 × 0.11 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ) T_min = 0.970, T_max = 0.989
16831 measured reflections
3770 independent reflections
2654 reflections with I > 2σ(I)
R_int = 0.031

Refinement

R[F² > 2σ(F²)] = 0.041
wR(F²) = 0.117
S = 1.02
3770 reflections
228 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.16 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N4—H4N⋯O2ⁱ	0.91 (2)	1.91 (2)	2.7860 (17)	160.9 (17)
N2—H2N⋯O4ⁱⁱ	0.912 (19)	1.984 (19)	2.8872 (18)	170.4 (17)
C2—H2⋯O2ⁱⁱⁱ	0.93	2.49	3.4082 (19)	171
C7—H7A⋯O3ⁱⁱ	0.96	2.54	3.458 (2)	159
C10—H10⋯O4^iv	0.93	2.45	3.3563 (18)	164
Symmetry codes: (i) $[x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (ii) x, y+1, z; (iii) -x, -y, -z+1; (iv) $[-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ) and PLATON (Spek, 2009 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ) and PLATON.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812012779/bt5857sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812012779/bt5857Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812012779/bt5857Isup3.cml

checkCIF report

Comment top

In continuation of our work on the synthesis and biological evaluation of various heterocyclic compounds, we, herein report the crystal structure of the title compound (I) Fig. 1.

Structure of the title compound is closely related to already published structures of 3,4-dimethyl-1-(2-pyridyl)pyrano(2,3-c)pyrazol-6 (1H)-one (Ramsay & Steel, 1985) and 3,4-dimethyl-1-phenylpyrano [2,3-c]pyrazol-6(1H)-one (Ahmad et al., 2011). There are two asymmetric molecules per unit cell and each molecule comprises of one pyranone ring fused with pyrazole ring. N-H···O hydrogen bonding interactions connect the molecules to zig-zag chains running along [1 0 1]. In addition, weak intermolecular C—H···O interactions connect these infinite chains to a three dimesional network (Table 1, Fig. 2).

Related literature top

For related structures, see: Ahmad et al. (2011); Ramsay & Steel (1985).

Experimental top

A mixture of hydrazine hydrate (1.0 mmole), ethyl acetoacetate (2.0 mmoles) was heated for one hour at 120°C followed by cooling to room temperature. The contents were triturated with diethyl ether, filtered and the residue obtained was crystallized from acetic acid. M.p. 246°C; Yield (87%).

Structure description top

In continuation of our work on the synthesis and biological evaluation of various heterocyclic compounds, we, herein report the crystal structure of the title compound (I) Fig. 1.

For related structures, see: Ahmad et al. (2011); Ramsay & Steel (1985).

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The labelled molecular structure of (I) showing molecules A and B with 50% displacement ellipsoids.
	Fig. 2. A perspective view showing hydrogen bond interactions drawn as dashed lines.

3,4-Dimethylpyrano[2,3-c]pyrazol-6(2H)-one top

Crystal data top

C₈H₈N₂O₂	F(000) = 688
M_r = 164.16	D_x = 1.443 Mg m⁻³
Monoclinic, P2₁/n	Melting point: 518 K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 13.6219 (3) Å	Cell parameters from 5051 reflections
b = 6.8766 (2) Å	θ = 2.5–27.8°
c = 16.2369 (4) Å	µ = 0.11 mm⁻¹
β = 96.091 (2)°	T = 296 K
V = 1512.36 (7) Å³	Needle, yellow
Z = 8	0.30 × 0.18 × 0.11 mm

Data collection top

Bruker Kappa APEXII CCD diffractometer	3770 independent reflections
Radiation source: fine-focus sealed tube	2654 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.031
φ and ω scans	θ_max = 28.3°, θ_min = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 2007)	h = −18→18
T_min = 0.970, T_max = 0.989	k = −8→9
16831 measured reflections	l = −21→18

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.041	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.117	w = 1/[σ²(F_o²) + (0.0553P)² + 0.3127P] where P = (F_o² + 2F_c²)/3
S = 1.02	(Δ/σ)_max < 0.001
3770 reflections	Δρ_max = 0.23 e Å⁻³
228 parameters	Δρ_min = −0.16 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0060 (10)

Crystal data top

C₈H₈N₂O₂	V = 1512.36 (7) Å³
M_r = 164.16	Z = 8
Monoclinic, P2₁/n	Mo Kα radiation
a = 13.6219 (3) Å	µ = 0.11 mm⁻¹
b = 6.8766 (2) Å	T = 296 K
c = 16.2369 (4) Å	0.30 × 0.18 × 0.11 mm
β = 96.091 (2)°

Data collection top

Bruker Kappa APEXII CCD diffractometer	3770 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2007)	2654 reflections with I > 2σ(I)
T_min = 0.970, T_max = 0.989	R_int = 0.031
16831 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.041	0 restraints
wR(F²) = 0.117	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	Δρ_max = 0.23 e Å⁻³
3770 reflections	Δρ_min = −0.16 e Å⁻³
228 parameters

Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
O1	0.14791 (7)	0.41930 (15)	0.44365 (6)	0.0399 (3)
O2	0.13549 (8)	0.13137 (18)	0.50096 (7)	0.0512 (3)
O3	0.00479 (8)	0.23381 (15)	0.19680 (7)	0.0417 (3)
O4	0.14510 (8)	0.19091 (16)	0.27386 (7)	0.0493 (3)
N1	0.14966 (10)	0.7225 (2)	0.38066 (8)	0.0445 (3)
N2	0.07651 (10)	0.8288 (2)	0.33725 (9)	0.0446 (3)
N3	−0.14217 (10)	0.2981 (2)	0.11578 (9)	0.0480 (4)
N4	−0.17201 (10)	0.4537 (2)	0.06663 (9)	0.0475 (4)
C1	0.09219 (11)	0.2599 (2)	0.46042 (9)	0.0372 (3)
C2	−0.01109 (11)	0.2563 (2)	0.43051 (9)	0.0375 (3)
H2	−0.0480	0.1485	0.4431	0.045*
C3	−0.05750 (10)	0.4004 (2)	0.38520 (9)	0.0341 (3)
C4	0.00154 (10)	0.5642 (2)	0.36819 (8)	0.0333 (3)
C5	0.10172 (10)	0.5654 (2)	0.39826 (9)	0.0351 (3)
C6	−0.01200 (11)	0.7428 (2)	0.32825 (9)	0.0375 (3)
C7	−0.10067 (12)	0.8367 (3)	0.28407 (10)	0.0487 (4)
H7A	−0.0840	0.9652	0.2671	0.073*
H7B	−0.1518	0.8446	0.3204	0.073*
H7C	−0.1236	0.7610	0.2362	0.073*
C8	−0.16479 (11)	0.3900 (3)	0.35436 (11)	0.0473 (4)
H8A	−0.1921	0.2711	0.3729	0.071*
H8B	−0.1724	0.3937	0.2949	0.071*
H8C	−0.1987	0.4986	0.3755	0.071*
C9	0.09864 (11)	0.2979 (2)	0.22481 (9)	0.0364 (3)
C10	0.13176 (10)	0.4804 (2)	0.19482 (9)	0.0368 (3)
H10	0.1960	0.5196	0.2121	0.044*
C11	0.07528 (10)	0.5986 (2)	0.14298 (9)	0.0332 (3)
C12	−0.02244 (10)	0.5304 (2)	0.11579 (8)	0.0333 (3)
C13	−0.05254 (11)	0.3506 (2)	0.14382 (9)	0.0363 (3)
C14	−0.10441 (11)	0.5942 (2)	0.06431 (9)	0.0380 (3)
C15	−0.12391 (13)	0.7747 (3)	0.01454 (11)	0.0509 (4)
H15A	−0.1839	0.7596	−0.0217	0.076*
H15B	−0.0700	0.7980	−0.0178	0.076*
H15C	−0.1304	0.8828	0.0510	0.076*
C16	0.11158 (13)	0.7903 (2)	0.11518 (11)	0.0481 (4)
H16A	0.1782	0.8107	0.1394	0.072*
H16B	0.0702	0.8923	0.1324	0.072*
H16C	0.1097	0.7911	0.0559	0.072*
H2N	0.0908 (14)	0.948 (3)	0.3166 (11)	0.058*
H4N	−0.2329 (15)	0.450 (3)	0.0380 (11)	0.058*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0295 (5)	0.0439 (6)	0.0448 (6)	0.0013 (4)	−0.0031 (4)	0.0031 (5)
O2	0.0412 (6)	0.0510 (7)	0.0590 (7)	0.0083 (5)	−0.0059 (5)	0.0141 (6)
O3	0.0400 (6)	0.0337 (5)	0.0503 (6)	−0.0062 (4)	−0.0005 (5)	0.0064 (5)
O4	0.0461 (7)	0.0435 (6)	0.0568 (7)	0.0067 (5)	−0.0016 (5)	0.0123 (5)
N1	0.0365 (7)	0.0427 (7)	0.0533 (8)	−0.0043 (6)	0.0002 (6)	0.0018 (6)
N2	0.0455 (8)	0.0362 (7)	0.0518 (8)	−0.0023 (6)	0.0037 (6)	0.0039 (6)
N3	0.0368 (7)	0.0496 (8)	0.0561 (9)	−0.0102 (6)	−0.0017 (6)	0.0001 (7)
N4	0.0332 (7)	0.0567 (9)	0.0504 (8)	−0.0009 (6)	−0.0051 (6)	−0.0039 (7)
C1	0.0344 (8)	0.0406 (8)	0.0361 (8)	0.0032 (6)	0.0014 (6)	0.0002 (6)
C2	0.0318 (7)	0.0398 (8)	0.0409 (8)	−0.0023 (6)	0.0028 (6)	0.0035 (6)
C3	0.0289 (7)	0.0405 (8)	0.0330 (7)	0.0008 (6)	0.0037 (6)	−0.0025 (6)
C4	0.0305 (7)	0.0368 (7)	0.0323 (7)	0.0015 (6)	0.0022 (6)	−0.0013 (6)
C5	0.0307 (7)	0.0387 (8)	0.0352 (8)	0.0001 (6)	0.0009 (6)	−0.0020 (6)
C6	0.0387 (8)	0.0369 (8)	0.0371 (8)	0.0023 (6)	0.0044 (6)	−0.0008 (6)
C7	0.0493 (10)	0.0450 (9)	0.0510 (10)	0.0092 (7)	0.0017 (8)	0.0084 (7)
C8	0.0304 (8)	0.0539 (10)	0.0564 (10)	−0.0017 (7)	−0.0001 (7)	0.0063 (8)
C9	0.0339 (8)	0.0348 (8)	0.0404 (8)	0.0027 (6)	0.0035 (6)	−0.0002 (6)
C10	0.0278 (7)	0.0380 (8)	0.0443 (8)	−0.0033 (6)	0.0021 (6)	−0.0009 (6)
C11	0.0333 (7)	0.0318 (7)	0.0353 (7)	−0.0013 (6)	0.0067 (6)	−0.0027 (6)
C12	0.0325 (7)	0.0327 (7)	0.0351 (8)	0.0012 (6)	0.0051 (6)	−0.0025 (6)
C13	0.0333 (8)	0.0367 (8)	0.0386 (8)	−0.0028 (6)	0.0023 (6)	−0.0015 (6)
C14	0.0351 (8)	0.0434 (8)	0.0352 (8)	0.0053 (7)	0.0022 (6)	−0.0046 (6)
C15	0.0498 (10)	0.0539 (10)	0.0477 (10)	0.0141 (8)	−0.0013 (8)	0.0043 (8)
C16	0.0486 (10)	0.0381 (9)	0.0577 (10)	−0.0075 (7)	0.0059 (8)	0.0065 (7)

Geometric parameters (Å, º) top

O1—C5	1.3603 (17)	C6—C7	1.485 (2)
O1—C1	1.3768 (18)	C7—H7A	0.9600
O2—C1	1.2165 (18)	C7—H7B	0.9600
O3—C13	1.3609 (18)	C7—H7C	0.9600
O3—C9	1.3828 (18)	C8—H8A	0.9600
O4—C9	1.2122 (18)	C8—H8B	0.9600
N1—C5	1.3094 (19)	C8—H8C	0.9600
N1—N2	1.3695 (19)	C9—C10	1.436 (2)
N2—C6	1.337 (2)	C10—C11	1.350 (2)
N2—H2N	0.912 (19)	C10—H10	0.9300
N3—C13	1.3076 (19)	C11—C12	1.4361 (19)
N3—N4	1.370 (2)	C11—C16	1.495 (2)
N4—C14	1.338 (2)	C12—C14	1.393 (2)
N4—H4N	0.91 (2)	C12—C13	1.394 (2)
C1—C2	1.439 (2)	C14—C15	1.489 (2)
C2—C3	1.351 (2)	C15—H15A	0.9600
C2—H2	0.9300	C15—H15B	0.9600
C3—C4	1.428 (2)	C15—H15C	0.9600
C3—C8	1.495 (2)	C16—H16A	0.9600
C4—C6	1.392 (2)	C16—H16B	0.9600
C4—C5	1.3998 (19)	C16—H16C	0.9600

C5—O1—C1	117.54 (11)	C3—C8—H8B	109.5
C13—O3—C9	117.92 (11)	H8A—C8—H8B	109.5
C5—N1—N2	101.55 (12)	C3—C8—H8C	109.5
C6—N2—N1	114.76 (13)	H8A—C8—H8C	109.5
C6—N2—H2N	125.6 (12)	H8B—C8—H8C	109.5
N1—N2—H2N	119.7 (12)	O4—C9—O3	114.99 (13)
C13—N3—N4	101.29 (13)	O4—C9—C10	126.33 (14)
C14—N4—N3	114.69 (13)	O3—C9—C10	118.68 (13)
C14—N4—H4N	126.9 (12)	C11—C10—C9	123.95 (13)
N3—N4—H4N	118.4 (12)	C11—C10—H10	118.0
O2—C1—O1	116.08 (13)	C9—C10—H10	118.0
O2—C1—C2	124.78 (15)	C10—C11—C12	116.31 (13)
O1—C1—C2	119.13 (13)	C10—C11—C16	122.29 (14)
C3—C2—C1	123.74 (14)	C12—C11—C16	121.39 (13)
C3—C2—H2	118.1	C14—C12—C13	103.33 (13)
C1—C2—H2	118.1	C14—C12—C11	137.69 (14)
C2—C3—C4	116.33 (13)	C13—C12—C11	118.98 (13)
C2—C3—C8	122.12 (14)	N3—C13—O3	120.62 (13)
C4—C3—C8	121.55 (13)	N3—C13—C12	115.28 (14)
C6—C4—C5	103.48 (13)	O3—C13—C12	124.10 (13)
C6—C4—C3	137.45 (14)	N4—C14—C12	105.41 (13)
C5—C4—C3	119.05 (13)	N4—C14—C15	122.24 (14)
N1—C5—O1	120.99 (13)	C12—C14—C15	132.35 (15)
N1—C5—C4	114.79 (13)	C14—C15—H15A	109.5
O1—C5—C4	124.21 (13)	C14—C15—H15B	109.5
N2—C6—C4	105.43 (13)	H15A—C15—H15B	109.5
N2—C6—C7	122.57 (14)	C14—C15—H15C	109.5
C4—C6—C7	132.00 (14)	H15A—C15—H15C	109.5
C6—C7—H7A	109.5	H15B—C15—H15C	109.5
C6—C7—H7B	109.5	C11—C16—H16A	109.5
H7A—C7—H7B	109.5	C11—C16—H16B	109.5
C6—C7—H7C	109.5	H16A—C16—H16B	109.5
H7A—C7—H7C	109.5	C11—C16—H16C	109.5
H7B—C7—H7C	109.5	H16A—C16—H16C	109.5
C3—C8—H8A	109.5	H16B—C16—H16C	109.5

C5—N1—N2—C6	−0.04 (18)	C3—C4—C6—C7	−0.6 (3)
C13—N3—N4—C14	0.15 (18)	C13—O3—C9—O4	177.73 (13)
C5—O1—C1—O2	179.84 (13)	C13—O3—C9—C10	−1.88 (19)
C5—O1—C1—C2	−0.76 (19)	O4—C9—C10—C11	−176.82 (15)
O2—C1—C2—C3	−179.65 (15)	O3—C9—C10—C11	2.8 (2)
O1—C1—C2—C3	1.0 (2)	C9—C10—C11—C12	−1.7 (2)
C1—C2—C3—C4	−0.8 (2)	C9—C10—C11—C16	178.13 (14)
C1—C2—C3—C8	179.23 (14)	C10—C11—C12—C14	−179.24 (16)
C2—C3—C4—C6	−177.72 (16)	C16—C11—C12—C14	0.9 (3)
C8—C3—C4—C6	2.3 (3)	C10—C11—C12—C13	0.0 (2)
C2—C3—C4—C5	0.4 (2)	C16—C11—C12—C13	−179.86 (14)
C8—C3—C4—C5	−179.65 (14)	N4—N3—C13—O3	179.70 (13)
N2—N1—C5—O1	−178.64 (13)	N4—N3—C13—C12	−0.08 (17)
N2—N1—C5—C4	0.29 (17)	C9—O3—C13—N3	−179.50 (13)
C1—O1—C5—N1	179.23 (13)	C9—O3—C13—C12	0.3 (2)
C1—O1—C5—C4	0.4 (2)	C14—C12—C13—N3	−0.02 (17)
C6—C4—C5—N1	−0.42 (17)	C11—C12—C13—N3	−179.50 (13)
C3—C4—C5—N1	−179.09 (13)	C14—C12—C13—O3	−179.79 (13)
C6—C4—C5—O1	178.48 (13)	C11—C12—C13—O3	0.7 (2)
C3—C4—C5—O1	−0.2 (2)	N3—N4—C14—C12	−0.16 (18)
N1—N2—C6—C4	−0.21 (18)	N3—N4—C14—C15	−179.68 (14)
N1—N2—C6—C7	179.12 (14)	C13—C12—C14—N4	0.10 (15)
C5—C4—C6—N2	0.35 (15)	C11—C12—C14—N4	179.43 (16)
C3—C4—C6—N2	178.62 (16)	C13—C12—C14—C15	179.54 (16)
C5—C4—C6—C7	−178.89 (16)	C11—C12—C14—C15	−1.1 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4N···O2ⁱ	0.91 (2)	1.91 (2)	2.7860 (17)	160.9 (17)
N2—H2N···O4ⁱⁱ	0.912 (19)	1.984 (19)	2.8872 (18)	170.4 (17)
C2—H2···O2ⁱⁱⁱ	0.93	2.49	3.4082 (19)	171
C7—H7A···O3ⁱⁱ	0.96	2.54	3.458 (2)	159
C10—H10···O4^iv	0.93	2.45	3.3563 (18)	164

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

Experimental details

Crystal data
Chemical formula	C₈H₈N₂O₂
M_r	164.16
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	296
a, b, c (Å)	13.6219 (3), 6.8766 (2), 16.2369 (4)
β (°)	96.091 (2)
V (Å³)	1512.36 (7)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.11
Crystal size (mm)	0.30 × 0.18 × 0.11

Data collection
Diffractometer	Bruker Kappa APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2007)
T_min, T_max	0.970, 0.989
No. of measured, independent and observed [I > 2σ(I)] reflections	16831, 3770, 2654
R_int	0.031
(sin θ/λ)_max (Å⁻¹)	0.668

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.041, 0.117, 1.02
No. of reflections	3770
No. of parameters	228
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.23, −0.16

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009), WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4N···O2ⁱ	0.91 (2)	1.91 (2)	2.7860 (17)	160.9 (17)
N2—H2N···O4ⁱⁱ	0.912 (19)	1.984 (19)	2.8872 (18)	170.4 (17)
C2—H2···O2ⁱⁱⁱ	0.93	2.49	3.4082 (19)	171.2
C7—H7A···O3ⁱⁱ	0.96	2.54	3.458 (2)	159.3
C10—H10···O4^iv	0.93	2.45	3.3563 (18)	163.6

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

Acknowledgements

The authors acknowledge the PCSIR Laboratories Complex, Lahore, Pakistan for the provision of facilities necessary to carry out the synthetic work.

References

Ahmad, N., Tahir, M. N., Khan, M. A., Ather, A. Q. & Khan, M. N. (2011). Acta Cryst. E67, o1021. Web of Science CSD CrossRef IUCr Journals Google Scholar
Bruker (2007). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Ramsay, C. G. & Steel, P. J. (1985). Acta Cryst. C41, 135–136. CSD CrossRef CAS Web of Science 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. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar