2-Isopropyl-6-methyl-pyrimidin-4(3H)-one.

The mol-ecular structure of the title compound, C(8)H(12)N(2)O, indicates that 2-isopropyl-6-methyl-pyrimidin-4-ol (the enol-form) undergoes an enol-to-keto tautomerism during the crystallization process. The pyrimidin-4(3H)-one group is essentially planar, with a maximum deviation of 0.081 (1) Å for the O atom. In the crystal structure, symmetry-related mol-ecules are linked into centrosymmetic dimers via pairs of inter-molecular N-H⋯O hydrogen bonds, generating R(2) (2)(8) rings. These dimers are stacked along the a axis.

Related literature

For applications of pyridinium derivatives, see: Condon et al. (1993 ▶); Maeno et al. (1990 ▶); Gilchrist (1997 ▶); Selby et al. (2002 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C8H12N2O

M = 152.20

Monoclinic,

a = 4.8627 (2) Å

b = 22.6320 (8) Å

c = 7.4228 (3) Å

β = 96.495 (2)°

V = 811.66 (5) Å3

Z = 4

Mo Kα radiation

μ = 0.08 mm−1

T = 100 K

0.74 × 0.14 × 0.07 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T min = 0.940, T max = 0.994

7806 measured reflections

2371 independent reflections

1958 reflections with I > 2σ(I)

R int = 0.026

Refinement

R[F 2 > 2σ(F 2)] = 0.039

wR(F 2) = 0.103

S = 1.06

2371 reflections

148 parameters

All H-atom parameters refined

Δρmax = 0.32 e Å−3

Δρmin = −0.20 e Å−3

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810034276/lh5121sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810034276/lh5121Isup2.hkl

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

C8H12N2O	F(000) = 328
Mr = 152.20	Dx = 1.245 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2995 reflections
a = 4.8627 (2) Å	θ = 2.9–30.0°
b = 22.6320 (8) Å	µ = 0.08 mm−1
c = 7.4228 (3) Å	T = 100 K
β = 96.495 (2)°	Needle, colourless
V = 811.66 (5) Å3	0.74 × 0.14 × 0.07 mm
Z = 4

Bruker SMART APEXII CCD area-detector diffractometer	2371 independent reflections
Radiation source: fine-focus sealed tube	1958 reflections with I > 2σ(I)
graphite	Rint = 0.026
φ and ω scans	θmax = 30.1°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −5→6
Tmin = 0.940, Tmax = 0.994	k = −26→31
7806 measured reflections	l = −10→10

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.103	All H-atom parameters refined
S = 1.06	w = 1/[σ2(Fo2) + (0.049P)2 + 0.163P] where P = (Fo2 + 2Fc2)/3
2371 reflections	(Δ/σ)max < 0.001
148 parameters	Δρmax = 0.32 e Å−3
0 restraints	Δρmin = −0.20 e Å−3

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

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.

	x	y	z	Uiso*/Ueq
O1	0.77782 (15)	0.03007 (3)	0.81600 (9)	0.02023 (18)
N1	0.43265 (17)	−0.13343 (3)	0.84671 (10)	0.01613 (18)
N2	0.75959 (17)	−0.06091 (3)	0.94759 (10)	0.01473 (17)
C1	0.64511 (19)	−0.11546 (4)	0.95755 (12)	0.01455 (19)
C2	0.6596 (2)	−0.01885 (4)	0.82081 (12)	0.0158 (2)
C3	0.4232 (2)	−0.03768 (4)	0.70385 (12)	0.0169 (2)
C4	0.32239 (19)	−0.09370 (4)	0.71759 (12)	0.0156 (2)
C5	0.0868 (2)	−0.11656 (5)	0.58916 (13)	0.0190 (2)
C6	0.7737 (2)	−0.15603 (4)	1.10544 (13)	0.01614 (19)
C7	0.8468 (3)	−0.21559 (5)	1.02578 (15)	0.0249 (2)
C8	0.5752 (2)	−0.16347 (5)	1.25028 (14)	0.0222 (2)
H1N2	0.915 (3)	−0.0510 (7)	1.0283 (19)	0.034 (4)*
H3A	0.338 (3)	−0.0101 (6)	0.6146 (18)	0.025 (3)*
H5A	−0.064 (3)	−0.1299 (6)	0.655 (2)	0.036 (4)*
H5B	0.011 (3)	−0.0864 (7)	0.503 (2)	0.044 (4)*
H5C	0.151 (3)	−0.1505 (6)	0.5237 (19)	0.034 (4)*
H6A	0.946 (3)	−0.1369 (5)	1.1613 (16)	0.018 (3)*
H7A	0.922 (3)	−0.2424 (6)	1.124 (2)	0.031 (3)*
H7B	0.984 (3)	−0.2117 (6)	0.9349 (19)	0.031 (4)*
H7C	0.681 (3)	−0.2348 (6)	0.9648 (19)	0.036 (4)*
H8A	0.661 (3)	−0.1874 (6)	1.3518 (19)	0.029 (3)*
H8B	0.408 (3)	−0.1849 (6)	1.1978 (18)	0.031 (4)*
H8C	0.519 (3)	−0.1249 (6)	1.2967 (19)	0.032 (4)*

	U11	U22	U33	U12	U13	U23
O1	0.0210 (4)	0.0159 (3)	0.0229 (4)	−0.0031 (3)	−0.0012 (3)	0.0032 (3)
N1	0.0159 (4)	0.0163 (4)	0.0157 (4)	−0.0010 (3)	0.0002 (3)	−0.0005 (3)
N2	0.0146 (4)	0.0143 (4)	0.0150 (4)	−0.0008 (3)	0.0005 (3)	0.0004 (3)
C1	0.0146 (4)	0.0146 (4)	0.0146 (4)	0.0003 (3)	0.0026 (3)	−0.0007 (3)
C2	0.0159 (4)	0.0161 (4)	0.0156 (4)	0.0005 (3)	0.0028 (3)	0.0007 (3)
C3	0.0165 (5)	0.0185 (4)	0.0153 (4)	0.0014 (3)	0.0006 (3)	0.0019 (3)
C4	0.0143 (4)	0.0185 (5)	0.0142 (4)	0.0005 (3)	0.0019 (3)	−0.0018 (3)
C5	0.0164 (5)	0.0227 (5)	0.0172 (4)	−0.0011 (4)	−0.0013 (3)	−0.0022 (4)
C6	0.0157 (4)	0.0151 (4)	0.0168 (4)	−0.0011 (3)	−0.0015 (3)	0.0009 (3)
C7	0.0301 (6)	0.0172 (5)	0.0260 (5)	0.0036 (4)	−0.0026 (4)	−0.0004 (4)
C8	0.0202 (5)	0.0268 (5)	0.0193 (5)	−0.0016 (4)	0.0012 (4)	0.0061 (4)

O1—C2	1.2497 (11)	C5—H5B	0.978 (16)
N1—C1	1.3105 (12)	C5—H5C	0.978 (15)
N1—C4	1.3777 (12)	C6—C7	1.5297 (14)
N2—C1	1.3595 (12)	C6—C8	1.5332 (14)
N2—C2	1.3874 (12)	C6—H6A	0.990 (12)
N2—H1N2	0.937 (15)	C7—H7A	0.985 (14)
C1—C6	1.5114 (13)	C7—H7B	1.004 (14)
C2—C3	1.4254 (13)	C7—H7C	0.980 (15)
C3—C4	1.3672 (13)	C8—H8A	0.982 (14)
C3—H3A	0.968 (13)	C8—H8B	0.987 (14)
C4—C5	1.4972 (13)	C8—H8C	0.988 (15)
C5—H5A	0.973 (16)
C1—N1—C4	116.83 (8)	H5A—C5—H5C	107.8 (12)
C1—N2—C2	123.08 (8)	H5B—C5—H5C	109.9 (12)
C1—N2—H1N2	119.2 (9)	C1—C6—C7	110.47 (8)
C2—N2—H1N2	117.7 (9)	C1—C6—C8	109.54 (8)
N1—C1—N2	123.11 (9)	C7—C6—C8	111.50 (8)
N1—C1—C6	119.97 (8)	C1—C6—H6A	107.5 (7)
N2—C1—C6	116.92 (8)	C7—C6—H6A	108.9 (7)
O1—C2—N2	120.02 (9)	C8—C6—H6A	108.9 (7)
O1—C2—C3	126.12 (9)	C6—C7—H7A	109.9 (8)
N2—C2—C3	113.86 (8)	C6—C7—H7B	112.5 (8)
C4—C3—C2	120.21 (9)	H7A—C7—H7B	109.4 (11)
C4—C3—H3A	121.2 (8)	C6—C7—H7C	110.8 (9)
C2—C3—H3A	118.6 (8)	H7A—C7—H7C	106.5 (12)
C3—C4—N1	122.85 (9)	H7B—C7—H7C	107.6 (11)
C3—C4—C5	121.86 (9)	C6—C8—H8A	110.7 (8)
N1—C4—C5	115.27 (8)	C6—C8—H8B	109.4 (8)
C4—C5—H5A	110.6 (9)	H8A—C8—H8B	106.8 (12)
C4—C5—H5B	112.3 (9)	C6—C8—H8C	111.6 (8)
H5A—C5—H5B	107.2 (12)	H8A—C8—H8C	109.3 (11)
C4—C5—H5C	108.9 (8)	H8B—C8—H8C	109.0 (11)
C4—N1—C1—N2	−1.11 (13)	C2—C3—C4—N1	2.79 (14)
C4—N1—C1—C6	178.69 (8)	C2—C3—C4—C5	−175.72 (8)
C2—N2—C1—N1	0.98 (14)	C1—N1—C4—C3	−0.79 (13)
C2—N2—C1—C6	−178.83 (8)	C1—N1—C4—C5	177.82 (8)
C1—N2—C2—O1	−178.41 (8)	N1—C1—C6—C7	52.88 (12)
C1—N2—C2—C3	0.98 (12)	N2—C1—C6—C7	−127.31 (9)
O1—C2—C3—C4	176.61 (9)	N1—C1—C6—C8	−70.32 (11)
N2—C2—C3—C4	−2.73 (13)	N2—C1—C6—C8	109.50 (9)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H1N2···O1i	0.937 (15)	1.844 (14)	2.7809 (11)	178.7 (10)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H1N2⋯O1i	0.937 (15)	1.844 (14)	2.7809 (11)	178.7 (10)

Symmetry code: (i) .