(5R*,11R*)-5-Methyl-1,2-dihydro-5,11-methano-5H,11H-1,3-thia-zolo[2,3-d][1,3,5]benzoxadiazo-cine.

The title compound, C(13)H(14)N(2)OS, crystallizes as a racemate in a non-chiral space group. It represents a conformationally restricted analogue of so-called Biginelli compounds known to exhibit multiple pharmacological activities and was selected for a single-crystal X-ray analysis in order to probe the chemical and spatial requirements of some kinds of activity. It was found that the state of hybridization of the formally aminic nitro-gen of the heterocycle is between sp(2) and sp(3) with the lone-pair electrons partially delocalized through conjugation with the sulfur atom rather than the double bond of the pyrimidine nucleus. As a result, the thia-zolo ring adopts a flat-envelope conformation and the puckering of the central pyrimidine ring is close to a half-chair. The critical phenyl ring is fixed in a pseudo-axial and perpendicular [dihedral angle 84.6 (1)°] orientation with respect to the pyrimidine ring via an oxygen bridge.

Related literature

For typical bond lengths, see: Abrahams (1956 ▶); Burke-Laing & Laing (1976 ▶). For the pharmacological activity of Biginelli compounds, see: Deres et al. (2003 ▶); Kappe (2000 ▶). For the synthesis of rigid dihydro­pyrimidine derivatives, see: Světlík et al. (1991 ▶).

Experimental

Crystal data

C13H14N2OS

M = 246.32

Monoclinic,

a = 14.307 (2) Å

b = 5.991 (1) Å

c = 15.203 (2) Å

β = 113.36 (1)°

V = 1196.3 (3) Å3

Z = 4

Mo Kα radiation

μ = 0.26 mm−1

T = 296 K

0.30 × 0.25 × 0.20 mm

Data collection

Siemens P4 diffractometer

Absorption correction: none

4529 measured reflections

3483 independent reflections

2517 reflections with I > 2σ(I)

R int = 0.028

3 standard reflections every 97 reflections intensity decay: none

Refinement

R[F 2 > 2σ(F 2)] = 0.053

wR(F 2) = 0.161

S = 1.05

3483 reflections

155 parameters

H-atom parameters constrained

Δρmax = 0.37 e Å−3

Δρmin = −0.24 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/S1600536809044729/im2147sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809044729/im2147Isup2.hkl

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

C13H14N2OS	F(000) = 520
Mr = 246.32	Dx = 1.368 Mg m−3
Monoclinic, P21/n	Melting point: 513 K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 14.307 (2) Å	Cell parameters from 20 reflections
b = 5.991 (1) Å	θ = 7–18°
c = 15.203 (2) Å	µ = 0.26 mm−1
β = 113.36 (1)°	T = 296 K
V = 1196.3 (3) Å3	Prism, colourless
Z = 4	0.30 × 0.25 × 0.20 mm

Siemens P4 diffractometer	Rint = 0.028
Radiation source: fine-focus sealed tube	θmax = 30.0°, θmin = 1.7°
graphite	h = −1→20
ω/2θ scans	k = −1→8
4529 measured reflections	l = −21→20
3483 independent reflections	3 standard reflections every 97 reflections
2517 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)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.161	H-atom parameters constrained
S = 1.05	w = 1/[σ2(Fo2) + (0.0855P)2 + 0.232P] where P = (Fo2 + 2Fc2)/3
3483 reflections	(Δ/σ)max = 0.001
155 parameters	Δρmax = 0.37 e Å−3
0 restraints	Δρmin = −0.23 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.

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
N1	0.24822 (12)	0.3305 (3)	−0.01176 (11)	0.0354 (3)
C2	0.20695 (13)	0.4743 (3)	0.02460 (12)	0.0316 (4)
N3	0.18468 (12)	0.6936 (3)	0.00041 (10)	0.0345 (3)
C4	0.18874 (14)	0.7633 (3)	−0.09082 (13)	0.0337 (4)
H4	0.1918	0.9264	−0.0938	0.040*
C5	0.28506 (14)	0.6602 (3)	−0.09323 (14)	0.0370 (4)
H5A	0.3443	0.7084	−0.0381	0.044*
H5B	0.2936	0.7054	−0.1509	0.044*
C6	0.27290 (14)	0.4073 (3)	−0.09162 (13)	0.0338 (4)
C7	0.09818 (14)	0.6755 (3)	−0.17604 (12)	0.0336 (4)
C8	0.10420 (13)	0.4666 (3)	−0.21460 (12)	0.0337 (4)
O1	0.19045 (11)	0.3365 (2)	−0.18067 (9)	0.0393 (3)
C9	0.02109 (17)	0.3840 (4)	−0.29390 (14)	0.0450 (5)
H9	0.0249	0.2451	−0.3195	0.054*
C10	−0.06598 (17)	0.5104 (5)	−0.33332 (15)	0.0552 (6)
H10	−0.1210	0.4555	−0.3857	0.066*
C11	−0.07307 (17)	0.7163 (5)	−0.29657 (16)	0.0565 (6)
H11	−0.1324	0.8000	−0.3241	0.068*
C12	0.00859 (16)	0.7986 (4)	−0.21826 (15)	0.0447 (5)
H12	0.0036	0.9379	−0.1935	0.054*
S1	0.17224 (4)	0.40002 (11)	0.12054 (4)	0.04879 (19)
C13	0.1245 (2)	0.6777 (5)	0.12630 (16)	0.0572 (6)
H13A	0.0601	0.6694	0.1333	0.069*
H13B	0.1727	0.7598	0.1802	0.069*
C14	0.11074 (18)	0.7907 (4)	0.03283 (16)	0.0497 (5)
H14A	0.0422	0.7665	−0.0145	0.060*
H14B	0.1220	0.9501	0.0425	0.060*
C15	0.36653 (17)	0.2829 (4)	−0.08909 (17)	0.0490 (5)
H15A	0.4235	0.3180	−0.0308	0.074*
H15B	0.3813	0.3269	−0.1429	0.074*
H15C	0.3539	0.1251	−0.0919	0.074*

	U11	U22	U33	U12	U13	U23
N1	0.0407 (8)	0.0327 (8)	0.0351 (7)	0.0028 (6)	0.0173 (6)	0.0016 (6)
C2	0.0295 (8)	0.0363 (9)	0.0270 (7)	−0.0032 (7)	0.0089 (6)	−0.0013 (6)
N3	0.0366 (8)	0.0346 (8)	0.0323 (7)	0.0010 (6)	0.0137 (6)	−0.0053 (6)
C4	0.0369 (9)	0.0261 (8)	0.0378 (9)	−0.0025 (7)	0.0144 (7)	−0.0001 (7)
C5	0.0347 (9)	0.0377 (10)	0.0399 (9)	−0.0056 (7)	0.0161 (7)	0.0001 (7)
C6	0.0347 (8)	0.0339 (9)	0.0346 (8)	0.0010 (7)	0.0156 (7)	−0.0015 (7)
C7	0.0361 (9)	0.0342 (9)	0.0301 (8)	−0.0007 (7)	0.0127 (7)	0.0052 (7)
C8	0.0368 (9)	0.0386 (9)	0.0273 (7)	−0.0058 (7)	0.0145 (7)	0.0006 (7)
O1	0.0456 (7)	0.0358 (7)	0.0353 (6)	−0.0002 (6)	0.0148 (6)	−0.0066 (5)
C9	0.0527 (12)	0.0514 (12)	0.0324 (9)	−0.0127 (10)	0.0185 (8)	−0.0035 (8)
C10	0.0420 (11)	0.0852 (18)	0.0314 (9)	−0.0130 (12)	0.0073 (8)	0.0010 (10)
C11	0.0391 (11)	0.0803 (18)	0.0417 (11)	0.0066 (11)	0.0072 (9)	0.0170 (12)
C12	0.0451 (10)	0.0470 (11)	0.0416 (10)	0.0078 (9)	0.0168 (8)	0.0104 (9)
S1	0.0577 (3)	0.0566 (4)	0.0390 (3)	−0.0027 (3)	0.0265 (2)	0.0012 (2)
C13	0.0631 (14)	0.0717 (16)	0.0452 (11)	0.0011 (12)	0.0306 (11)	−0.0175 (11)
C14	0.0528 (12)	0.0471 (12)	0.0556 (12)	0.0061 (10)	0.0283 (10)	−0.0107 (10)
C15	0.0442 (11)	0.0516 (13)	0.0592 (13)	0.0102 (10)	0.0289 (10)	0.0000 (10)

N1—C2	1.287 (2)	C8—C9	1.405 (3)
N1—C6	1.466 (2)	C9—C10	1.375 (3)
C2—N3	1.368 (2)	C9—H9	0.9300
C2—S1	1.7738 (18)	C10—C11	1.375 (4)
N3—C14	1.454 (2)	C10—H10	0.9300
N3—C4	1.471 (2)	C11—C12	1.387 (3)
C4—C7	1.518 (2)	C11—H11	0.9300
C4—C5	1.524 (3)	C12—H12	0.9300
C4—H4	0.9800	S1—C13	1.814 (3)
C5—C6	1.527 (3)	C13—C14	1.515 (3)
C5—H5A	0.9700	C13—H13A	0.9700
C5—H5B	0.9700	C13—H13B	0.9700
C6—O1	1.462 (2)	C14—H14A	0.9700
C6—C15	1.520 (3)	C14—H14B	0.9700
C7—C12	1.395 (3)	C15—H15A	0.9600
C7—C8	1.399 (3)	C15—H15B	0.9600
C8—O1	1.375 (2)	C15—H15C	0.9600
C2—N1—C6	116.60 (16)	C10—C9—C8	119.5 (2)
N1—C2—N3	128.72 (17)	C10—C9—H9	120.3
N1—C2—S1	120.73 (15)	C8—C9—H9	120.3
N3—C2—S1	110.54 (13)	C11—C10—C9	121.1 (2)
C2—N3—C14	114.61 (17)	C11—C10—H10	119.4
C2—N3—C4	115.73 (14)	C9—C10—H10	119.4
C14—N3—C4	120.80 (16)	C10—C11—C12	119.7 (2)
N3—C4—C7	111.52 (14)	C10—C11—H11	120.2
N3—C4—C5	106.36 (14)	C12—C11—H11	120.2
C7—C4—C5	108.24 (15)	C11—C12—C7	121.0 (2)
N3—C4—H4	110.2	C11—C12—H12	119.5
C7—C4—H4	110.2	C7—C12—H12	119.5
C5—C4—H4	110.2	C2—S1—C13	92.48 (10)
C4—C5—C6	106.99 (15)	C14—C13—S1	106.02 (14)
C4—C5—H5A	110.3	C14—C13—H13A	110.5
C6—C5—H5A	110.3	S1—C13—H13A	110.5
C4—C5—H5B	110.3	C14—C13—H13B	110.5
C6—C5—H5B	110.3	S1—C13—H13B	110.5
H5A—C5—H5B	108.6	H13A—C13—H13B	108.7
O1—C6—N1	107.76 (14)	N3—C14—C13	107.34 (18)
O1—C6—C15	105.11 (15)	N3—C14—H14A	110.2
N1—C6—C15	108.93 (16)	C13—C14—H14A	110.2
O1—C6—C5	109.15 (15)	N3—C14—H14B	110.2
N1—C6—C5	113.02 (15)	C13—C14—H14B	110.2
C15—C6—C5	112.47 (17)	H14A—C14—H14B	108.5
C12—C7—C8	118.55 (18)	C6—C15—H15A	109.5
C12—C7—C4	121.83 (18)	C6—C15—H15B	109.5
C8—C7—C4	119.62 (16)	H15A—C15—H15B	109.5
O1—C8—C7	123.01 (16)	C6—C15—H15C	109.5
O1—C8—C9	116.78 (18)	H15A—C15—H15C	109.5
C7—C8—C9	120.17 (18)	H15B—C15—H15C	109.5
C8—O1—C6	117.24 (14)
C6—N1—C2—N3	−1.7 (3)	C12—C7—C8—O1	177.30 (17)
C6—N1—C2—S1	179.22 (12)	C4—C7—C8—O1	−2.0 (3)
N1—C2—N3—C14	161.48 (18)	C12—C7—C8—C9	−0.3 (3)
S1—C2—N3—C14	−19.39 (19)	C4—C7—C8—C9	−179.59 (17)
N1—C2—N3—C4	13.7 (3)	C7—C8—O1—C6	9.4 (2)
S1—C2—N3—C4	−167.15 (12)	C9—C8—O1—C6	−172.92 (16)
C2—N3—C4—C7	73.81 (19)	N1—C6—O1—C8	81.42 (18)
C14—N3—C4—C7	−71.8 (2)	C15—C6—O1—C8	−162.51 (16)
C2—N3—C4—C5	−44.00 (19)	C5—C6—O1—C8	−41.7 (2)
C14—N3—C4—C5	170.38 (16)	O1—C8—C9—C10	−177.58 (18)
N3—C4—C5—C6	62.31 (18)	C7—C8—C9—C10	0.1 (3)
C7—C4—C5—C6	−57.65 (19)	C8—C9—C10—C11	0.1 (3)
C2—N1—C6—O1	−97.83 (18)	C9—C10—C11—C12	−0.2 (4)
C2—N1—C6—C15	148.63 (17)	C10—C11—C12—C7	0.1 (3)
C2—N1—C6—C5	22.9 (2)	C8—C7—C12—C11	0.2 (3)
C4—C5—C6—O1	66.42 (18)	C4—C7—C12—C11	179.48 (19)
C4—C5—C6—N1	−53.5 (2)	N1—C2—S1—C13	179.86 (16)
C4—C5—C6—C15	−177.33 (16)	N3—C2—S1—C13	0.65 (14)
N3—C4—C7—C12	91.3 (2)	C2—S1—C13—C14	16.47 (17)
C5—C4—C7—C12	−152.05 (17)	C2—N3—C14—C13	32.1 (2)
N3—C4—C7—C8	−89.41 (19)	C4—N3—C14—C13	178.03 (17)
C5—C4—C7—C8	27.3 (2)	S1—C13—C14—N3	−28.8 (2)