2-Methyl-1,10b-dihydro-5H-pyrazolo[1,5-c][1,3]benzoxazin-5-one.

In the title compound, C(11)H(10)N(2)O(2), a potential inhibitor of the cyclo-oxygenase-2 isoenzyme, the pyrazoline ring exists in a flat-envelope conformation while the puckering of the central oxazine ring is more severe. As a result, the mol-ecule as a whole is non-planar. The formal sp(3) pyrazoline N atom is sp(2) hybridized, with the lone-pair electrons delocalized through conjugation with the carbonyl group rather than the double bond of the pyrazoline ring.

Related literature

For cyclo­oxygenase-2 (COX-2), see: Jahng et al. (2004 ▶); Ramatunge et al. (2004 ▶); Subbaramaiah et al. (2002 ▶). For bond parameters, see: Allen et al. (1987 ▶); Burke-Laing & Laing (1976 ▶). For background to the synthesis, see: Palomer et al. (2002 ▶); Světlík et al. (2005 ▶).

Experimental

Crystal data

C11H10N2O2

M = 202.21

Orthorhombic,

a = 7.240 (2) Å

b = 8.835 (2) Å

c = 15.755 (4) Å

V = 1007.8 (4) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 296 K

0.30 × 0.25 × 0.20 mm

Data collection

Siemens P4 diffractometer

Absorption correction: none

2285 measured reflections

1674 independent reflections

1343 reflections with I > 2σ(I)

R int = 0.021

3 standard reflections every 97 reflections intensity decay: none

Refinement

R[F 2 > 2σ(F 2)] = 0.055

wR(F 2) = 0.161

S = 0.96

1674 reflections

137 parameters

H-atom parameters constrained

Δρmax = 0.26 e Å−3

Δρmin = −0.22 e Å−3

Data collection: XSCANS (Siemens, 1991 ▶); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809012173/tk2391sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809012173/tk2391Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C11H10N2O2	Dx = 1.333 Mg m−3
Mr = 202.21	Melting point: 433 K
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 20 reflections
a = 7.240 (2) Å	θ = 7–18°
b = 8.835 (2) Å	µ = 0.09 mm−1
c = 15.755 (4) Å	T = 296 K
V = 1007.8 (4) Å3	Prism, colourless
Z = 4	0.30 × 0.25 × 0.20 mm
F(000) = 424

Siemens P4 diffractometer	Rint = 0.021
Radiation source: fine-focus sealed tube	θmax = 30.0°, θmin = 2.6°
graphite	h = −1→10
ω/2θ scans	k = −1→12
2285 measured reflections	l = −1→22
1674 independent reflections	3 standard reflections every 97 reflections
1343 reflections with I > 2σ(I)	intensity decay: none

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)] = 0.055	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.161	H-atom parameters constrained
S = 0.96	w = 1/[σ2(Fo2) + (0.058P)2 + 0.7099P] where P = (Fo2 + 2Fc2)/3
1674 reflections	(Δ/σ)max = 0.003
137 parameters	Δρmax = 0.26 e Å−3
0 restraints	Δρmin = −0.22 e Å−3

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.Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane)- 6.4736 (0.0083) x + 3.9501 (0.0194) y + 0.3894 (0.0333) z = 1.1812 (0.0071)* 0.0059 (0.0012) C1 * -0.0108 (0.0022) C2 * 0.0108 (0.0022) N3 * -0.0060 (0.0012) N4 - 0.3338 (0.0055) C10BRms deviation of fitted atoms = 0.00877.0450 (0.0031) x - 0.1068 (0.0223) y + 3.6269 (0.0223) z = 1.0294 (0.0128)Angle to previous plane (with approximate e.s.d.) = 29.57 (0.16)* -0.0027 (0.0010) O6 * 0.0053 (0.0019) C6A * -0.0050 (0.0018) C10A * 0.0024 (0.0009) C10B -0.6963 (0.0054) N4 - 0.5900 (0.0063) C5Rms deviation of fitted atoms = 0.00417.0642 (0.0025) x - 0.1723 (0.0086) y + 3.4371 (0.0150) z = 0.9846 (0.0059)Angle to previous plane (with approximate e.s.d.) = 0.82 (0.08)* -0.0143 (0.0023) O6 * -0.0087 (0.0029) C6A * 0.0109 (0.0030) C7 * 0.0160 (0.0032) C8 * -0.0063 (0.0031) C9 * -0.0177 (0.0029) C10 * -0.0034 (0.0027) C10A * 0.0234 (0.0023) C10BRms deviation of fitted atoms = 0.0140- 6.2356 (0.0052) x + 4.4868 (0.0103) y - 0.2799 (0.0136) z = 1.4163 (0.0043)Angle to previous plane (with approximate e.s.d.) = 31.34 (0.08)* -0.2463 (0.0027) C10B * 0.1374 (0.0029) C1 * 0.0194 (0.0039) C2 * -0.0476 (0.0032) N3 * -0.0351 (0.0028) N4 * 0.0138 (0.0033) C5 * 0.1614 (0.0027) O6 * 0.0426 (0.0034) C11 * -0.0456 (0.0025) O5Rms deviation of fitted atoms = 0.1123

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.

	x	y	z	Uiso*/Ueq
C1	0.1064 (5)	0.4867 (4)	−0.11974 (19)	0.0540 (8)
H1A	0.0197	0.5671	−0.1328	0.065*
H1B	0.2107	0.4926	−0.1582	0.065*
C2	0.0157 (5)	0.3341 (4)	−0.1229 (2)	0.0600 (9)
N3	−0.0199 (4)	0.2741 (3)	−0.05137 (18)	0.0581 (7)
N4	0.0479 (4)	0.3750 (3)	0.00991 (16)	0.0484 (6)
C5	0.0201 (5)	0.3524 (4)	0.0925 (2)	0.0523 (8)
O5	−0.0494 (5)	0.2447 (3)	0.12627 (15)	0.0761 (9)
O6	0.0794 (4)	0.4709 (3)	0.14279 (14)	0.0583 (7)
C6A	0.1009 (4)	0.6157 (3)	0.1075 (2)	0.0475 (7)
C7	0.0800 (5)	0.7370 (4)	0.1622 (2)	0.0594 (9)
H7	0.0532	0.7219	0.2193	0.071*
C8	0.1000 (6)	0.8811 (4)	0.1297 (3)	0.0675 (11)
H8	0.0873	0.9643	0.1654	0.081*
C9	0.1389 (5)	0.9035 (4)	0.0445 (3)	0.0669 (11)
H9	0.1507	1.0011	0.0230	0.080*
C10	0.1601 (5)	0.7788 (4)	−0.0086 (3)	0.0569 (8)
H10	0.1858	0.7931	−0.0659	0.068*
C10A	0.1430 (4)	0.6339 (3)	0.0233 (2)	0.0431 (6)
C10B	0.1680 (5)	0.4926 (3)	−0.02737 (18)	0.0429 (6)
H10B	0.2971	0.4598	−0.0235	0.051*
C11	−0.0392 (8)	0.2580 (7)	−0.2042 (3)	0.0990 (19)
H11A	−0.0912	0.1605	−0.1918	0.149*
H11B	0.0677	0.2458	−0.2396	0.149*
H11C	−0.1290	0.3190	−0.2331	0.149*

	U11	U22	U33	U12	U13	U23
C1	0.060 (2)	0.0602 (18)	0.0414 (14)	−0.0014 (17)	0.0052 (15)	−0.0004 (14)
C2	0.062 (2)	0.071 (2)	0.0464 (16)	−0.011 (2)	0.0099 (16)	−0.0100 (16)
N3	0.0687 (18)	0.0535 (14)	0.0521 (14)	−0.0145 (16)	0.0099 (14)	−0.0113 (13)
N4	0.0602 (15)	0.0425 (12)	0.0424 (12)	−0.0082 (13)	0.0002 (12)	0.0010 (10)
C5	0.069 (2)	0.0450 (15)	0.0434 (14)	−0.0054 (17)	−0.0015 (16)	0.0022 (13)
O5	0.116 (2)	0.0590 (14)	0.0528 (13)	−0.0199 (17)	0.0073 (15)	0.0105 (12)
O6	0.0811 (18)	0.0495 (12)	0.0442 (11)	−0.0036 (13)	−0.0074 (13)	0.0021 (9)
C6A	0.0454 (15)	0.0438 (15)	0.0532 (17)	−0.0029 (14)	−0.0089 (14)	−0.0026 (13)
C7	0.058 (2)	0.0586 (19)	0.0614 (19)	0.0009 (18)	−0.0116 (17)	−0.0163 (17)
C8	0.061 (2)	0.0489 (18)	0.092 (3)	0.0013 (18)	−0.013 (2)	−0.023 (2)
C9	0.055 (2)	0.0353 (14)	0.110 (3)	−0.0010 (15)	−0.005 (2)	−0.0001 (18)
C10	0.0453 (16)	0.0542 (19)	0.071 (2)	−0.0042 (15)	−0.0013 (17)	0.0076 (18)
C10A	0.0356 (13)	0.0404 (13)	0.0533 (16)	0.0044 (12)	−0.0012 (13)	−0.0006 (12)
C10B	0.0420 (14)	0.0383 (13)	0.0484 (15)	−0.0037 (12)	0.0046 (13)	0.0062 (12)
C11	0.106 (4)	0.137 (4)	0.054 (2)	−0.050 (4)	0.016 (2)	−0.038 (3)

C1—C2	1.501 (5)	C7—C8	1.380 (5)
C1—C10B	1.523 (4)	C7—H7	0.9300
C1—H1A	0.9700	C8—C9	1.385 (6)
C1—H1B	0.9700	C8—H8	0.9300
C2—N3	1.272 (4)	C9—C10	1.393 (5)
C2—C11	1.499 (5)	C9—H9	0.9300
N3—N4	1.403 (4)	C10—C10A	1.381 (4)
N4—C5	1.332 (4)	C10—H10	0.9300
N4—C10B	1.477 (4)	C10A—C10B	1.493 (4)
C5—O5	1.200 (4)	C10B—H10B	0.9800
C5—O6	1.381 (4)	C11—H11A	0.9600
O6—C6A	1.404 (4)	C11—H11B	0.9600
C6A—C10A	1.371 (4)	C11—H11C	0.9600
C6A—C7	1.383 (4)
C2—C1—C10B	101.0 (3)	C7—C8—H8	119.6
C2—C1—H1A	111.6	C9—C8—H8	119.6
C10B—C1—H1A	111.6	C8—C9—C10	119.5 (3)
C2—C1—H1B	111.6	C8—C9—H9	120.3
C10B—C1—H1B	111.6	C10—C9—H9	120.3
H1A—C1—H1B	109.4	C10A—C10—C9	120.3 (3)
N3—C2—C1	115.7 (3)	C10A—C10—H10	119.8
N3—C2—C11	121.1 (4)	C9—C10—H10	119.8
C1—C2—C11	123.2 (3)	C6A—C10A—C10	118.8 (3)
C2—N3—N4	105.9 (3)	C6A—C10A—C10B	116.5 (3)
C5—N4—N3	121.6 (3)	C10—C10A—C10B	124.7 (3)
C5—N4—C10B	125.7 (3)	N4—C10B—C10A	107.7 (2)
N3—N4—C10B	112.3 (2)	N4—C10B—C1	100.6 (3)
O5—C5—N4	127.9 (3)	C10A—C10B—C1	120.3 (3)
O5—C5—O6	118.5 (3)	N4—C10B—H10B	109.2
N4—C5—O6	113.6 (3)	C10A—C10B—H10B	109.2
C5—O6—C6A	119.9 (2)	C1—C10B—H10B	109.2
C10A—C6A—C7	122.4 (3)	C2—C11—H11A	109.5
C10A—C6A—O6	121.0 (3)	C2—C11—H11B	109.5
C7—C6A—O6	116.6 (3)	H11A—C11—H11B	109.5
C8—C7—C6A	118.2 (4)	C2—C11—H11C	109.5
C8—C7—H7	120.9	H11A—C11—H11C	109.5
C6A—C7—H7	120.9	H11B—C11—H11C	109.5
C7—C8—C9	120.8 (3)
C10B—C1—C2—N3	14.6 (4)	C8—C9—C10—C10A	−0.2 (6)
C10B—C1—C2—C11	−168.2 (4)	C7—C6A—C10A—C10	−1.9 (5)
C1—C2—N3—N4	−2.2 (4)	O6—C6A—C10A—C10	179.1 (3)
C11—C2—N3—N4	−179.4 (4)	C7—C6A—C10A—C10B	177.9 (3)
C2—N3—N4—C5	174.6 (4)	O6—C6A—C10A—C10B	−1.2 (4)
C2—N3—N4—C10B	−12.4 (4)	C9—C10—C10A—C6A	1.5 (5)
N3—N4—C5—O5	5.9 (7)	C9—C10—C10A—C10B	−178.3 (3)
C10B—N4—C5—O5	−166.1 (4)	C5—N4—C10B—C10A	−40.0 (4)
N3—N4—C5—O6	−173.5 (3)	N3—N4—C10B—C10A	147.3 (3)
C10B—N4—C5—O6	14.4 (5)	C5—N4—C10B—C1	−166.7 (3)
O5—C5—O6—C6A	−158.0 (4)	N3—N4—C10B—C1	20.6 (3)
N4—C5—O6—C6A	21.5 (5)	C6A—C10A—C10B—N4	30.5 (4)
C5—O6—C6A—C10A	−28.5 (5)	C10—C10A—C10B—N4	−149.8 (3)
C5—O6—C6A—C7	152.4 (3)	C6A—C10A—C10B—C1	144.7 (3)
C10A—C6A—C7—C8	1.0 (5)	C10—C10A—C10B—C1	−35.6 (5)
O6—C6A—C7—C8	−180.0 (3)	C2—C1—C10B—N4	−19.1 (3)
C6A—C7—C8—C9	0.4 (6)	C2—C1—C10B—C10A	−137.0 (3)
C7—C8—C9—C10	−0.8 (6)