4-[(5R*,10bR*)-2-Methyl-1,10b-dihydro-pyrazolo[1,5-c][1,3]benzoxazin-5-yl]benzoic acid.

In the title compound, C(18)H(16)N(2)O(3), a potential inhibitor of the cyclo-oxygenase-2 isoenzyme, the pyrazoline ring exists in a flattened envelope conformation with one C atom deviating by 0.463 Å from the mean plane of the remaining four atoms. The puckering of the central oxazine ring is more severe, with one N atom and one C atom displaced by 0.235 (6) and 0.370 (2) Å, respectively, on opposite sides of the mean plane defined by the other four atoms; the conformation is that of a half-chair. As a result, the mol-ecule as a whole is not planar. The carboxyl group is involved in an inter-molecular O-H⋯N hydrogen bond, which links the mol-ecules into centrosymmetric dimers.

Related literature

For related literature, see: Palomer et al. (2002 ▶); Subbaramaiah et al. (2002 ▶); Světlík et al. (2005 ▶).

Experimental

Crystal data

C18H16N2O3

M = 308.33

Triclinic,

a = 6.638 (2) Å

b = 10.997 (3) Å

c = 11.141 (3) Å

α = 70.78 (2)°

β = 80.85 (3)°

γ = 79.15 (2)°

V = 750.1 (4) Å3

Z = 2

Mo Kα radiation

μ = 0.09 mm−1

T = 296 (2) K

0.30 × 0.20 × 0.15 mm

Data collection

Siemens P4 diffractometer

Absorption correction: none

5341 measured reflections

4312 independent reflections

3216 reflections with I > 2σ(I)

R int = 0.019

3 standard reflections every 97 reflections intensity decay: none

Refinement

R[F 2 > 2σ(F 2)] = 0.051

wR(F 2) = 0.152

S = 1.01

4312 reflections

210 parameters

H-atom parameters constrained

Δρmax = 0.29 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, 2003 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808003607/bi2280sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808003607/bi2280Isup2.hkl

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

C18H16N2O3	Z = 2
Mr = 308.33	F000 = 324
Triclinic, P1	Dx = 1.365 Mg m−3
Hall symbol: -P 1	Melting point: 477 K
a = 6.638 (2) Å	Mo Kα radiation λ = 0.71073 Å
b = 10.997 (3) Å	Cell parameters from 20 reflections
c = 11.141 (3) Å	θ = 7–18º
α = 70.78 (2)º	µ = 0.09 mm−1
β = 80.85 (3)º	T = 296 (2) K
γ = 79.15 (2)º	Prism, colourless
V = 750.1 (4) Å3	0.30 × 0.20 × 0.15 mm

Siemens P4 diffractometer	Rint = 0.019
Radiation source: fine-focus sealed tube	θmax = 30.0º
Monochromator: graphite	θmin = 2.0º
T = 296(2) K	h = −1→9
ω/2θ scans	k = −14→14
Absorption correction: none	l = −15→15
5341 measured reflections	3 standard reflections
4312 independent reflections	every 97 reflections
3216 reflections with I > 2σ(I)	intensity decay: none

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)] = 0.051	H-atom parameters constrained
wR(F2) = 0.152	w = 1/[σ2(Fo2) + (0.0853P)2 + 0.0987P] where P = (Fo2 + 2Fc2)/3
S = 1.01	(Δ/σ)max = 0.001
4312 reflections	Δρmax = 0.29 e Å−3
210 parameters	Δρmin = −0.22 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

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.

	x	y	z	Uiso*/Ueq
C1	0.3065 (2)	0.63515 (13)	0.03856 (13)	0.0364 (3)
H1A	0.3369	0.6320	−0.0485	0.044*
H1B	0.4338	0.6149	0.0780	0.044*
C2	0.1553 (2)	0.54630 (12)	0.11427 (12)	0.0324 (3)
N3	0.01255 (17)	0.59887 (10)	0.18002 (10)	0.0314 (2)
N4	0.05040 (17)	0.72620 (10)	0.16410 (10)	0.0304 (2)
C5	−0.1328 (2)	0.81721 (13)	0.17228 (12)	0.0342 (3)
H5	−0.0911	0.8976	0.1736	0.041*
O6	−0.25382 (16)	0.84950 (11)	0.06661 (9)	0.0440 (3)
C7	−0.1451 (2)	0.87381 (13)	−0.05137 (12)	0.0371 (3)
C8	−0.2589 (3)	0.93655 (15)	−0.15442 (14)	0.0479 (4)
H8	−0.3999	0.9630	−0.1409	0.057*
C9	−0.1623 (3)	0.95933 (18)	−0.27641 (16)	0.0586 (5)
H9	−0.2381	1.0010	−0.3458	0.070*
C10	0.0466 (3)	0.92058 (17)	−0.29635 (15)	0.0560 (5)
H10	0.1116	0.9354	−0.3792	0.067*
C11	0.1589 (3)	0.86000 (14)	−0.19372 (13)	0.0449 (4)
H11	0.3003	0.8352	−0.2079	0.054*
C12	0.0646 (2)	0.83525 (12)	−0.06896 (12)	0.0347 (3)
C13	0.1871 (2)	0.76641 (13)	0.04385 (12)	0.0330 (3)
H13	0.2808	0.8222	0.0510	0.040*
C14	0.1724 (2)	0.40903 (14)	0.11858 (15)	0.0418 (3)
H14A	0.2925	0.3598	0.1589	0.063*
H14B	0.1840	0.4044	0.0332	0.063*
H14C	0.0517	0.3737	0.1665	0.063*
C15	−0.2727 (2)	0.76809 (12)	0.29245 (12)	0.0329 (3)
C16	−0.2086 (2)	0.75161 (17)	0.40981 (14)	0.0448 (4)
H16	−0.0830	0.7752	0.4137	0.054*
C17	−0.3307 (3)	0.70033 (17)	0.52093 (14)	0.0462 (4)
H17	−0.2865	0.6890	0.5995	0.055*
C18	−0.5184 (2)	0.66557 (13)	0.51636 (12)	0.0342 (3)
C19	−0.5837 (2)	0.68431 (14)	0.39930 (13)	0.0374 (3)
H19	−0.7103	0.6621	0.3952	0.045*
C20	−0.4614 (2)	0.73595 (14)	0.28820 (13)	0.0381 (3)
H20	−0.5070	0.7492	0.2096	0.046*
C21	−0.6403 (2)	0.60087 (13)	0.63696 (13)	0.0361 (3)
O7	−0.5895 (2)	0.58142 (13)	0.74163 (10)	0.0520 (3)
O8	−0.80628 (16)	0.56450 (11)	0.61698 (10)	0.0454 (3)
H8A	−0.8571	0.5179	0.6845	0.068*

	U11	U22	U33	U12	U13	U23
C1	0.0382 (7)	0.0364 (7)	0.0318 (6)	−0.0088 (5)	0.0038 (5)	−0.0084 (5)
C2	0.0362 (6)	0.0317 (6)	0.0286 (6)	−0.0074 (5)	−0.0017 (5)	−0.0077 (5)
N3	0.0364 (6)	0.0285 (5)	0.0281 (5)	−0.0088 (4)	−0.0002 (4)	−0.0065 (4)
N4	0.0362 (5)	0.0290 (5)	0.0256 (5)	−0.0104 (4)	0.0017 (4)	−0.0072 (4)
C5	0.0423 (7)	0.0310 (6)	0.0282 (6)	−0.0086 (5)	0.0016 (5)	−0.0082 (5)
O6	0.0434 (5)	0.0498 (6)	0.0273 (5)	−0.0018 (5)	−0.0005 (4)	−0.0009 (4)
C7	0.0514 (8)	0.0290 (6)	0.0273 (6)	−0.0098 (6)	−0.0004 (5)	−0.0034 (5)
C8	0.0585 (9)	0.0417 (8)	0.0359 (7)	−0.0042 (7)	−0.0097 (7)	−0.0015 (6)
C9	0.0890 (14)	0.0478 (9)	0.0316 (7)	−0.0059 (9)	−0.0143 (8)	−0.0009 (6)
C10	0.0856 (13)	0.0474 (9)	0.0279 (7)	−0.0115 (9)	0.0037 (8)	−0.0058 (6)
C11	0.0624 (9)	0.0362 (7)	0.0313 (7)	−0.0126 (7)	0.0087 (6)	−0.0072 (5)
C12	0.0507 (8)	0.0253 (6)	0.0270 (6)	−0.0126 (5)	0.0018 (5)	−0.0055 (4)
C13	0.0368 (6)	0.0331 (6)	0.0288 (6)	−0.0134 (5)	0.0036 (5)	−0.0079 (5)
C14	0.0464 (8)	0.0351 (7)	0.0449 (8)	−0.0074 (6)	−0.0004 (6)	−0.0149 (6)
C15	0.0403 (7)	0.0287 (6)	0.0276 (6)	−0.0059 (5)	0.0024 (5)	−0.0081 (5)
C16	0.0447 (8)	0.0600 (9)	0.0340 (7)	−0.0227 (7)	0.0018 (6)	−0.0147 (6)
C17	0.0524 (9)	0.0628 (10)	0.0270 (6)	−0.0203 (7)	−0.0002 (6)	−0.0139 (6)
C18	0.0396 (7)	0.0322 (6)	0.0289 (6)	−0.0055 (5)	0.0031 (5)	−0.0098 (5)
C19	0.0359 (7)	0.0410 (7)	0.0329 (6)	−0.0087 (5)	−0.0014 (5)	−0.0076 (5)
C20	0.0426 (7)	0.0417 (7)	0.0277 (6)	−0.0085 (6)	−0.0042 (5)	−0.0063 (5)
C21	0.0405 (7)	0.0337 (6)	0.0311 (6)	−0.0055 (5)	0.0038 (5)	−0.0097 (5)
O7	0.0637 (7)	0.0646 (7)	0.0285 (5)	−0.0204 (6)	0.0024 (5)	−0.0126 (5)
O8	0.0457 (6)	0.0506 (6)	0.0336 (5)	−0.0165 (5)	0.0032 (4)	−0.0029 (4)

C1—C2	1.4934 (19)	C11—C12	1.3915 (19)
C1—C13	1.5249 (19)	C11—H11	0.930
C1—H1A	0.970	C12—C13	1.5101 (19)
C1—H1B	0.970	C13—H13	0.980
C2—N3	1.2730 (17)	C14—H14A	0.960
C2—C14	1.4776 (19)	C14—H14B	0.960
N3—N4	1.4178 (15)	C14—H14C	0.960
N4—C5	1.4335 (18)	C15—C20	1.376 (2)
N4—C13	1.4793 (17)	C15—C16	1.3839 (19)
C5—O6	1.4409 (17)	C16—C17	1.379 (2)
C5—C15	1.5047 (18)	C16—H16	0.930
C5—H5	0.980	C17—C18	1.384 (2)
O6—C7	1.3637 (17)	C17—H17	0.930
C7—C12	1.379 (2)	C18—C19	1.3783 (19)
C7—C8	1.387 (2)	C18—C21	1.4856 (19)
C8—C9	1.371 (2)	C19—C20	1.380 (2)
C8—H8	0.930	C19—H19	0.930
C9—C10	1.377 (3)	C20—H20	0.930
C9—H9	0.930	C21—O7	1.2053 (17)
C10—C11	1.375 (2)	C21—O8	1.3140 (18)
C10—H10	0.930	O8—H8A	0.820
C2—C1—C13	100.79 (11)	C7—C12—C13	120.90 (12)
C2—C1—H1A	111.6	C11—C12—C13	121.16 (14)
C13—C1—H1A	111.6	N4—C13—C12	111.46 (11)
C2—C1—H1B	111.6	N4—C13—C1	100.98 (10)
C13—C1—H1B	111.6	C12—C13—C1	112.93 (11)
H1A—C1—H1B	109.4	N4—C13—H13	110.4
N3—C2—C14	122.55 (13)	C12—C13—H13	110.4
N3—C2—C1	113.23 (12)	C1—C13—H13	110.4
C14—C2—C1	124.16 (12)	C2—C14—H14A	109.5
C2—N3—N4	108.71 (11)	C2—C14—H14B	109.5
N3—N4—C5	114.05 (10)	H14A—C14—H14B	109.5
N3—N4—C13	107.26 (9)	C2—C14—H14C	109.5
C5—N4—C13	114.20 (10)	H14A—C14—H14C	109.5
N4—C5—O6	113.73 (11)	H14B—C14—H14C	109.5
N4—C5—C15	112.11 (11)	C20—C15—C16	119.21 (13)
O6—C5—C15	106.99 (11)	C20—C15—C5	121.22 (12)
N4—C5—H5	107.9	C16—C15—C5	119.55 (13)
O6—C5—H5	107.9	C17—C16—C15	120.12 (14)
C15—C5—H5	107.9	C17—C16—H16	119.9
C7—O6—C5	115.49 (11)	C15—C16—H16	119.9
O6—C7—C12	122.64 (12)	C16—C17—C18	120.50 (13)
O6—C7—C8	116.04 (14)	C16—C17—H17	119.8
C12—C7—C8	121.29 (14)	C18—C17—H17	119.8
C9—C8—C7	119.60 (17)	C19—C18—C17	119.28 (13)
C9—C8—H8	120.2	C19—C18—C21	120.86 (13)
C7—C8—H8	120.2	C17—C18—C21	119.74 (13)
C8—C9—C10	120.15 (16)	C18—C19—C20	120.10 (13)
C8—C9—H9	119.9	C18—C19—H19	119.9
C10—C9—H9	119.9	C20—C19—H19	119.9
C11—C10—C9	119.92 (15)	C15—C20—C19	120.77 (13)
C11—C10—H10	120.0	C15—C20—H20	119.6
C9—C10—H10	120.0	C19—C20—H20	119.6
C10—C11—C12	121.10 (16)	O7—C21—O8	123.78 (13)
C10—C11—H11	119.4	O7—C21—C18	123.50 (14)
C12—C11—H11	119.4	O8—C21—C18	112.71 (12)
C7—C12—C11	117.93 (14)	C21—O8—H8A	109.5
C13—C1—C2—N3	−15.79 (15)	N3—N4—C13—C1	−29.67 (12)
C13—C1—C2—C14	166.98 (12)	C5—N4—C13—C1	−157.08 (11)
C14—C2—N3—N4	174.46 (11)	C7—C12—C13—N4	11.07 (17)
C1—C2—N3—N4	−2.82 (15)	C11—C12—C13—N4	−167.94 (12)
C2—N3—N4—C5	148.89 (11)	C7—C12—C13—C1	123.94 (13)
C2—N3—N4—C13	21.40 (13)	C11—C12—C13—C1	−55.08 (17)
N3—N4—C5—O6	−68.94 (13)	C2—C1—C13—N4	26.12 (12)
C13—N4—C5—O6	54.89 (15)	C2—C1—C13—C12	−93.01 (13)
N3—N4—C5—C15	52.60 (14)	N4—C5—C15—C20	−112.18 (15)
C13—N4—C5—C15	176.43 (10)	O6—C5—C15—C20	13.15 (17)
N4—C5—O6—C7	−44.40 (16)	N4—C5—C15—C16	66.12 (17)
C15—C5—O6—C7	−168.75 (11)	O6—C5—C15—C16	−168.55 (12)
C5—O6—C7—C12	17.97 (19)	C20—C15—C16—C17	1.7 (2)
C5—O6—C7—C8	−164.03 (12)	C5—C15—C16—C17	−176.64 (14)
O6—C7—C8—C9	−177.12 (14)	C15—C16—C17—C18	−0.4 (3)
C12—C7—C8—C9	0.9 (2)	C16—C17—C18—C19	−0.8 (2)
C7—C8—C9—C10	−0.3 (3)	C16—C17—C18—C21	175.18 (15)
C8—C9—C10—C11	−0.6 (3)	C17—C18—C19—C20	0.7 (2)
C9—C10—C11—C12	0.9 (3)	C21—C18—C19—C20	−175.28 (13)
O6—C7—C12—C11	177.24 (13)	C16—C15—C20—C19	−1.9 (2)
C8—C7—C12—C11	−0.7 (2)	C5—C15—C20—C19	176.45 (13)
O6—C7—C12—C13	−1.8 (2)	C18—C19—C20—C15	0.7 (2)
C8—C7—C12—C13	−179.70 (13)	C19—C18—C21—O7	179.54 (14)
C10—C11—C12—C7	−0.2 (2)	C17—C18—C21—O7	3.6 (2)
C10—C11—C12—C13	178.82 (14)	C19—C18—C21—O8	1.05 (19)
N3—N4—C13—C12	90.51 (12)	C17—C18—C21—O8	−174.89 (13)
C5—N4—C13—C12	−36.89 (15)

D—H···A	D—H	H···A	D···A	D—H···A
O8—H8A···N3i	0.82	1.93	2.7356 (17)	168

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O8—H8A⋯N3i	0.82	1.93	2.7356 (17)	168

Symmetry code: (i) .