4-Amino-2,8-dimethyl-6H-pyrimido[1,2-a][1,3,5]triazin-6-one.

In the title compound, C(8)H(9)N(5)O, the mean planes through the pyrimidine and triazine rings form a dihedral angle of 2.83 (16)°. The amino group adopts a trigonal-planar configuration and forms an intra-molecular resonance-assisted N-H⋯O=C hydrogen bond with the carbonyl group. In the crystal, mol-ecules are linked via inter-molecular N-H⋯N hydrogen bonds into chains of C(2) (2)(6)[R(2) (2)(6)] motif. The molecules form two types of sheet parallel to (201) and (01), respectively.

Related literature

For reviews on the synthesis and biological activity of fused 1,3,5-triazines see: Dolzhenko et al. (2006 ▶, 2008a ▶). For the synthesis and structural and biological investigations of pyrimido[1,2-a][1,3,5]triazines and their benzo-fused analogues, see Agasimundin et al. (1985 ▶); Dolzhenko et al. (2008b ▶, 2009 ▶). For the graph-set analysis of hydrogen bonding, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C8H9N5O

M = 191.20

Orthorhombic,

a = 11.1369 (19) Å

b = 18.913 (3) Å

c = 4.0311 (7) Å

V = 849.1 (3) Å3

Z = 4

Mo Kα radiation

μ = 0.11 mm−1

T = 100 K

0.60 × 0.08 × 0.06 mm

Data collection

Bruker SMART APEX CCD diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 2001 ▶) T min = 0.938, T max = 0.994

5774 measured reflections

1119 independent reflections

1019 reflections with I > 2σ(I)

R int = 0.050

Refinement

R[F 2 > 2σ(F 2)] = 0.053

wR(F 2) = 0.117

S = 1.15

1119 reflections

137 parameters

1 restraint

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.33 e Å−3

Δρmin = −0.25 e Å−3

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810027522/ez2220sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810027522/ez2220Isup2.hkl

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

C8H9N5O	Dx = 1.496 Mg m−3
Mr = 191.20	Melting point: 545 K
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 614 reflections
a = 11.1369 (19) Å	θ = 2.8–26.8°
b = 18.913 (3) Å	µ = 0.11 mm−1
c = 4.0311 (7) Å	T = 100 K
V = 849.1 (3) Å3	Needle, colourless
Z = 4	0.60 × 0.08 × 0.06 mm
F(000) = 400

Bruker SMART APEX CCD diffractometer	1119 independent reflections
Radiation source: fine-focus sealed tube	1019 reflections with I > 2σ(I)
graphite	Rint = 0.050
φ and ω scans	θmax = 27.5°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	h = −13→14
Tmin = 0.938, Tmax = 0.994	k = −24→22
5774 measured reflections	l = −5→4

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) = 0.117	H atoms treated by a mixture of independent and constrained refinement
S = 1.15	w = 1/[σ2(Fo2) + (0.053P)2 + 0.4545P] where P = (Fo2 + 2Fc2)/3
1119 reflections	(Δ/σ)max < 0.001
137 parameters	Δρmax = 0.33 e Å−3
1 restraint	Δρmin = −0.25 e Å−3

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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
O1	0.61240 (19)	0.88225 (11)	−0.2411 (7)	0.0229 (6)
N1	0.3706 (2)	0.71578 (13)	0.3214 (8)	0.0145 (6)
N2	0.5341 (2)	0.67258 (13)	−0.0011 (7)	0.0137 (6)
N3	0.4963 (2)	0.79702 (13)	0.0265 (7)	0.0119 (5)
N4	0.3255 (2)	0.83294 (13)	0.3415 (7)	0.0138 (6)
N5	0.6531 (2)	0.74865 (15)	−0.2904 (7)	0.0154 (6)
H51	0.673 (3)	0.793 (2)	−0.326 (11)	0.018 (9)*
H52	0.689 (3)	0.7098 (19)	−0.349 (11)	0.019 (9)*
C1	0.4393 (3)	0.66472 (15)	0.2008 (8)	0.0134 (6)
C2	0.5625 (2)	0.73778 (15)	−0.0888 (8)	0.0128 (6)
C3	0.3965 (2)	0.78262 (15)	0.2314 (8)	0.0121 (6)
C4	0.3465 (2)	0.90073 (15)	0.2475 (9)	0.0139 (6)
C5	0.4418 (3)	0.91978 (16)	0.0552 (8)	0.0147 (6)
H5	0.4531	0.9683	0.0019	0.018*
C6	0.5246 (3)	0.86906 (15)	−0.0674 (8)	0.0155 (7)
C7	0.4091 (3)	0.59100 (15)	0.3046 (10)	0.0191 (7)
H7A	0.4559	0.5784	0.5017	0.029*
H7B	0.4282	0.5582	0.1239	0.029*
H7C	0.3232	0.5880	0.3562	0.029*
C8	0.2543 (3)	0.95324 (15)	0.3617 (9)	0.0182 (7)
H8A	0.1796	0.9460	0.2381	0.027*
H8B	0.2840	1.0013	0.3224	0.027*
H8C	0.2392	0.9467	0.5992	0.027*

	U11	U22	U33	U12	U13	U23
O1	0.0225 (11)	0.0152 (11)	0.0310 (14)	−0.0048 (8)	0.0116 (12)	0.0017 (11)
N1	0.0125 (11)	0.0128 (12)	0.0183 (14)	−0.0008 (9)	0.0027 (11)	0.0007 (11)
N2	0.0132 (11)	0.0131 (13)	0.0149 (13)	−0.0011 (9)	−0.0009 (11)	−0.0029 (11)
N3	0.0101 (10)	0.0113 (12)	0.0144 (13)	−0.0013 (8)	0.0024 (10)	−0.0011 (10)
N4	0.0116 (10)	0.0137 (12)	0.0162 (13)	−0.0004 (9)	0.0017 (11)	−0.0011 (11)
N5	0.0139 (12)	0.0123 (13)	0.0200 (15)	0.0017 (10)	0.0064 (12)	−0.0007 (12)
C1	0.0124 (12)	0.0152 (14)	0.0126 (15)	−0.0014 (11)	−0.0034 (12)	−0.0002 (13)
C2	0.0101 (12)	0.0167 (15)	0.0114 (14)	0.0023 (11)	−0.0002 (12)	−0.0034 (13)
C3	0.0108 (12)	0.0161 (14)	0.0096 (14)	−0.0022 (10)	0.0013 (12)	−0.0003 (13)
C4	0.0142 (13)	0.0136 (14)	0.0139 (15)	−0.0001 (10)	−0.0048 (12)	−0.0030 (14)
C5	0.0190 (14)	0.0085 (14)	0.0165 (16)	−0.0027 (11)	−0.0031 (13)	−0.0007 (12)
C6	0.0156 (13)	0.0122 (15)	0.0187 (17)	−0.0050 (11)	−0.0018 (13)	0.0009 (13)
C7	0.0215 (14)	0.0126 (14)	0.0232 (18)	−0.0004 (11)	0.0046 (15)	0.0005 (13)
C8	0.0182 (13)	0.0154 (15)	0.0209 (16)	0.0021 (11)	0.0018 (13)	−0.0010 (14)

O1—C6	1.228 (4)	N5—H52	0.87 (4)
N1—C1	1.324 (4)	C1—C7	1.494 (4)
N1—C3	1.346 (4)	C4—C5	1.363 (4)
N2—C2	1.321 (4)	C4—C8	1.501 (4)
N2—C1	1.342 (4)	C5—C6	1.420 (4)
N3—C3	1.411 (4)	C5—H5	0.9500
N3—C2	1.420 (4)	C7—H7A	0.9800
N3—C6	1.449 (4)	C7—H7B	0.9800
N4—C3	1.314 (4)	C7—H7C	0.9800
N4—C4	1.357 (4)	C8—H8A	0.9800
N5—C2	1.311 (4)	C8—H8B	0.9800
N5—H51	0.89 (4)	C8—H8C	0.9800
C1—N1—C3	117.5 (3)	C5—C4—C8	122.2 (3)
C2—N2—C1	117.0 (2)	C4—C5—C6	121.7 (3)
C3—N3—C2	116.6 (2)	C4—C5—H5	119.2
C3—N3—C6	120.4 (2)	C6—C5—H5	119.2
C2—N3—C6	122.9 (2)	O1—C6—C5	125.3 (3)
C3—N4—C4	119.1 (3)	O1—C6—N3	120.9 (3)
C2—N5—H51	116 (2)	C5—C6—N3	113.8 (3)
C2—N5—H52	113 (2)	C1—C7—H7A	109.5
H51—N5—H52	130 (3)	C1—C7—H7B	109.5
N1—C1—N2	126.6 (3)	H7A—C7—H7B	109.5
N1—C1—C7	116.6 (3)	C1—C7—H7C	109.5
N2—C1—C7	116.8 (3)	H7A—C7—H7C	109.5
N5—C2—N2	119.7 (3)	H7B—C7—H7C	109.5
N5—C2—N3	118.6 (3)	C4—C8—H8A	109.5
N2—C2—N3	121.6 (3)	C4—C8—H8B	109.5
N4—C3—N1	117.4 (3)	H8A—C8—H8B	109.5
N4—C3—N3	122.1 (3)	C4—C8—H8C	109.5
N1—C3—N3	120.5 (3)	H8A—C8—H8C	109.5
N4—C4—C5	122.9 (3)	H8B—C8—H8C	109.5
N4—C4—C8	114.9 (3)
C3—N1—C1—N2	0.9 (5)	C2—N3—C3—N4	−177.1 (3)
C3—N1—C1—C7	179.8 (3)	C6—N3—C3—N4	0.7 (4)
C2—N2—C1—N1	0.2 (5)	C2—N3—C3—N1	2.8 (4)
C2—N2—C1—C7	−178.8 (3)	C6—N3—C3—N1	−179.4 (3)
C1—N2—C2—N5	−178.8 (3)	C3—N4—C4—C5	−3.2 (5)
C1—N2—C2—N3	0.4 (4)	C3—N4—C4—C8	174.9 (3)
C3—N3—C2—N5	177.4 (3)	N4—C4—C5—C6	1.6 (5)
C6—N3—C2—N5	−0.3 (4)	C8—C4—C5—C6	−176.3 (3)
C3—N3—C2—N2	−1.8 (4)	C4—C5—C6—O1	−179.9 (3)
C6—N3—C2—N2	−179.5 (3)	C4—C5—C6—N3	1.0 (4)
C4—N4—C3—N1	−177.9 (3)	C3—N3—C6—O1	178.8 (3)
C4—N4—C3—N3	2.0 (4)	C2—N3—C6—O1	−3.6 (4)
C1—N1—C3—N4	177.5 (3)	C3—N3—C6—C5	−2.1 (4)
C1—N1—C3—N3	−2.4 (4)	C2—N3—C6—C5	175.5 (3)

D—H···A	D—H	H···A	D···A	D—H···A
N5—H51···O1	0.89 (4)	1.84 (4)	2.575 (3)	139 (3)
N5—H51···N1i	0.89 (4)	2.63 (4)	2.961 (4)	103 (3)
N5—H52···N4i	0.87 (4)	2.12 (4)	2.876 (4)	144 (3)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N5—H51⋯O1	0.89 (4)	1.84 (4)	2.575 (3)	139 (3)
N5—H51⋯N1i	0.89 (4)	2.63 (4)	2.961 (4)	103 (3)
N5—H52⋯N4i	0.87 (4)	2.12 (4)	2.876 (4)	144 (3)

Symmetry code: (i) .