Phthalic acid–4,6-dimethyl­pyrimidin-2-amine (1/1)

In the crystal structure of the title compound, C₈H₆O₄·C₆H₉N₃, the two molecules inter­act via N—H...O and O—H...N hydrogen bonds, resulting in centrosymmetric clusters.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.047
• wR factor = 0.135
• Data-to-parameter ratio = 13.9

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S1. Comment

In this paper, the structure of the title compound, (I), a 1:1 adduct of phthalic acid and 4,6-dimethylpyrimidin-2-amine is reported. (Fig. 1). The geometrical parameters of 4,6-dimethylpyrimidin-2-amine molecule in (I) are similar to those in methyl N-[4-(4,6-dimethylpyrimidin-2-ylamino)thiocarbonyl]carbamate (Ren et al., 2005). The heterocycle is essentially planar, within 0.014 (4) Å, and the dihedral angle between this plane and the benzene ring of the phthalic acid molecule is 21.3 (2) °. The crystal structure is stabilized by N—H···O and O—H···N hydrogen bonds (Fig. 2 and Table 1) to result in tetrameric associations of molecules, generated by inversion.

Related literature

For related literature, see: Ren et al. (2005).

S2. Experimental

A mixture of phthalic acid (0.01 mol) and 4,6-dimethylpyrimidin-2-amine (0.01 mol) in ethanol (20 ml) was refluxed for 0.5 h, and cooled. The solution was kept at room temperature for 12 d. Natural evaporation gave yellow blocks of (I) suitable for X-ray analysis.

S3. Refinement

The N-bound H atoms were located in a difference map and their positions and U_iso values were freely refined.

The other H atoms were positioned geometrically (C—H = 0.93 Å, O—H = 0.82 Å) and refined as riding with U_iso(H) = 1.2U_eq(C, O).

Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997; software used to prepare material for publication: SHELXTL.

Figures

Fig. 1. A tetrameric cluster in (I), drawn with 30% probability ellipsoids (arbitrary spheres for the H atoms; C-bound H atoms omitted for clarity). Hydrogen bonds are indicated by dashed lines. Symmetry code: (i) -x, -y, 1 - z.

Phthalic acid–4,6-dimethylpyrimidin-2-amine (1/1)

Crystal data

C8H6O4·C6H9N3	F(000) = 608
Mr = 289.29	Dx = 1.389 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1525 reflections
a = 14.472 (7) Å	θ = 2.5–24.9°
b = 7.083 (4) Å	µ = 0.10 mm^−1
c = 14.563 (8) Å	T = 294 K
β = 112.108 (8)°	Block, yellow
V = 1383.1 (12) Å^3	0.24 × 0.22 × 0.18 mm
Z = 4

Data collection

Bruker SMART CCD diffractometer	2801 independent reflections
Radiation source: fine-focus sealed tube	1550 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.047
ω scans	θmax = 26.4°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 1997)	h = −18→17
Tmin = 0.976, Tmax = 0.982	k = −7→8
7676 measured reflections	l = −18→15

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.047	Hydrogen site location: difmap and geom
wR(F^2) = 0.135	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0663P)^2] where P = (Fo^2 + 2Fc^2)/3
2801 reflections	(Δ/σ)max = 0.001
202 parameters	Δρmax = 0.19 e Å^−3
3 restraints	Δρmin = −0.22 e Å^−3

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.32059 (11)	0.0730 (2)	0.57966 (11)	0.0495 (5)
H1	0.2975	0.1014	0.6213	0.074*
O2	0.17859 (12)	0.1937 (2)	0.47642 (12)	0.0536 (5)
O3	0.10073 (11)	−0.1554 (3)	0.37463 (12)	0.0545 (5)
O4	0.04800 (11)	−0.0115 (2)	0.22987 (12)	0.0491 (5)
H4	−0.0064	−0.0495	0.2275	0.074*
N1	0.26384 (13)	0.1281 (3)	0.72801 (14)	0.0374 (5)
N2	0.13632 (13)	0.1101 (2)	0.79262 (13)	0.0382 (5)
N3	0.09888 (15)	0.1281 (3)	0.62636 (15)	0.0518 (6)
C1	0.25648 (17)	0.1130 (3)	0.49214 (17)	0.0380 (5)
C2	0.28825 (15)	0.0563 (3)	0.41096 (16)	0.0343 (5)
C3	0.38602 (16)	0.0813 (3)	0.42031 (17)	0.0408 (6)
H3	0.4329	0.1256	0.4797	0.049*
C4	0.41430 (17)	0.0416 (3)	0.34297 (18)	0.0448 (6)
H4A	0.4804	0.0580	0.3501	0.054*
C5	0.34617 (17)	−0.0222 (3)	0.25536 (19)	0.0452 (6)
H5	0.3658	−0.0489	0.2029	0.054*
C6	0.24853 (17)	−0.0469 (3)	0.24448 (18)	0.0408 (6)
H6	0.2020	−0.0879	0.1841	0.049*
C7	0.21890 (15)	−0.0116 (3)	0.32215 (16)	0.0344 (5)
C8	0.11693 (16)	−0.0646 (3)	0.31263 (17)	0.0377 (5)
C9	0.16713 (16)	0.1230 (3)	0.71695 (17)	0.0370 (5)
C10	0.20528 (16)	0.1091 (3)	0.88369 (16)	0.0377 (5)
C11	0.30461 (17)	0.1199 (3)	0.89960 (17)	0.0444 (6)
H11	0.3525	0.1231	0.9637	0.053*
C12	0.33204 (16)	0.1260 (3)	0.81947 (17)	0.0393 (6)
C13	0.43803 (16)	0.1279 (4)	0.8298 (2)	0.0547 (7)
H13A	0.4579	0.0026	0.8200	0.082*
H13B	0.4790	0.1710	0.8950	0.082*
H13C	0.4458	0.2112	0.7812	0.082*
C14	0.16923 (18)	0.0961 (4)	0.96640 (17)	0.0509 (7)
H14A	0.1267	0.2017	0.9636	0.076*
H14B	0.2252	0.0973	1.0284	0.076*
H14C	0.1325	−0.0191	0.9606	0.076*
H3A	0.0349 (8)	0.138 (3)	0.6152 (15)	0.050 (7)*
H3B	0.1167 (14)	0.147 (3)	0.5749 (12)	0.051 (7)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0374 (10)	0.0815 (13)	0.0298 (10)	0.0072 (8)	0.0131 (8)	0.0016 (8)
O2	0.0453 (10)	0.0756 (12)	0.0422 (11)	0.0223 (9)	0.0192 (9)	0.0043 (8)
O3	0.0366 (10)	0.0792 (13)	0.0503 (12)	−0.0038 (8)	0.0192 (9)	0.0189 (9)
O4	0.0318 (9)	0.0744 (12)	0.0411 (10)	−0.0030 (8)	0.0139 (9)	0.0074 (8)
N1	0.0288 (10)	0.0498 (12)	0.0334 (11)	−0.0021 (8)	0.0114 (9)	−0.0012 (8)
N2	0.0342 (11)	0.0511 (12)	0.0306 (11)	−0.0025 (9)	0.0135 (9)	−0.0026 (8)
N3	0.0286 (12)	0.0970 (17)	0.0292 (12)	0.0010 (11)	0.0104 (10)	0.0023 (11)
C1	0.0330 (13)	0.0462 (14)	0.0366 (14)	−0.0003 (11)	0.0153 (12)	0.0009 (11)
C2	0.0329 (12)	0.0393 (13)	0.0318 (13)	0.0028 (10)	0.0133 (11)	0.0045 (9)
C3	0.0279 (12)	0.0564 (16)	0.0369 (14)	0.0034 (11)	0.0110 (11)	0.0051 (11)
C4	0.0301 (13)	0.0609 (16)	0.0474 (16)	0.0045 (11)	0.0192 (13)	0.0072 (12)
C5	0.0435 (14)	0.0560 (16)	0.0457 (16)	0.0021 (12)	0.0279 (13)	−0.0014 (12)
C6	0.0398 (14)	0.0502 (15)	0.0342 (13)	−0.0019 (11)	0.0161 (11)	−0.0051 (10)
C7	0.0314 (12)	0.0396 (13)	0.0352 (13)	0.0012 (9)	0.0159 (11)	0.0026 (10)
C8	0.0328 (13)	0.0463 (14)	0.0347 (14)	0.0008 (10)	0.0135 (12)	−0.0020 (11)
C9	0.0331 (13)	0.0443 (14)	0.0339 (14)	−0.0036 (10)	0.0127 (12)	−0.0035 (10)
C10	0.0403 (14)	0.0416 (14)	0.0312 (13)	−0.0020 (10)	0.0132 (12)	−0.0024 (10)
C11	0.0368 (14)	0.0584 (16)	0.0314 (14)	−0.0009 (11)	0.0053 (11)	−0.0030 (11)
C12	0.0324 (12)	0.0424 (14)	0.0401 (15)	−0.0038 (10)	0.0104 (12)	−0.0051 (10)
C13	0.0347 (14)	0.0735 (19)	0.0535 (18)	−0.0026 (12)	0.0139 (13)	0.0005 (13)
C14	0.0509 (16)	0.0693 (18)	0.0356 (15)	0.0022 (13)	0.0196 (13)	0.0005 (12)

Geometric parameters (Å, º)

O1—C1	1.294 (3)	C4—C5	1.363 (3)
O1—H1	0.8200	C4—H4A	0.9300
O2—C1	1.206 (2)	C5—C6	1.373 (3)
O3—C8	1.201 (3)	C5—H5	0.9300
O4—C8	1.298 (3)	C6—C7	1.375 (3)
O4—H4	0.8200	C6—H6	0.9300
N1—C12	1.326 (3)	C7—C8	1.478 (3)
N1—C9	1.348 (3)	C10—C11	1.369 (3)
N2—C10	1.326 (3)	C10—C14	1.485 (3)
N2—C9	1.338 (3)	C11—C12	1.367 (3)
N3—C9	1.318 (3)	C11—H11	0.9300
N3—H3A	0.881 (9)	C12—C13	1.484 (3)
N3—H3B	0.890 (19)	C13—H13A	0.9600
C1—C2	1.476 (3)	C13—H13B	0.9600
C2—C3	1.381 (3)	C13—H13C	0.9600
C2—C7	1.391 (3)	C14—H14A	0.9600
C3—C4	1.365 (3)	C14—H14B	0.9600
C3—H3	0.9300	C14—H14C	0.9600
C1—O1—H1	109.5	O3—C8—O4	123.6 (2)
C8—O4—H4	109.5	O3—C8—C7	122.4 (2)
C12—N1—C9	117.81 (19)	O4—C8—C7	113.88 (19)
C10—N2—C9	117.72 (19)	N3—C9—N2	118.0 (2)
C9—N3—H3A	121.8 (13)	N3—C9—N1	118.2 (2)
C9—N3—H3B	120.1 (13)	N2—C9—N1	123.8 (2)
H3A—N3—H3B	116.8 (15)	N2—C10—C11	121.1 (2)
O2—C1—O1	124.3 (2)	N2—C10—C14	116.7 (2)
O2—C1—C2	121.8 (2)	C11—C10—C14	122.2 (2)
O1—C1—C2	113.89 (19)	C12—C11—C10	118.7 (2)
C3—C2—C7	119.3 (2)	C12—C11—H11	120.6
C3—C2—C1	120.2 (2)	C10—C11—H11	120.6
C7—C2—C1	120.37 (19)	N1—C12—C11	120.8 (2)
C4—C3—C2	120.4 (2)	N1—C12—C13	116.9 (2)
C4—C3—H3	119.8	C11—C12—C13	122.3 (2)
C2—C3—H3	119.8	C12—C13—H13A	109.5
C5—C4—C3	120.3 (2)	C12—C13—H13B	109.5
C5—C4—H4A	119.8	H13A—C13—H13B	109.5
C3—C4—H4A	119.8	C12—C13—H13C	109.5
C4—C5—C6	120.1 (2)	H13A—C13—H13C	109.5
C4—C5—H5	120.0	H13B—C13—H13C	109.5
C6—C5—H5	120.0	C10—C14—H14A	109.5
C5—C6—C7	120.5 (2)	C10—C14—H14B	109.5
C5—C6—H6	119.7	H14A—C14—H14B	109.5
C7—C6—H6	119.7	C10—C14—H14C	109.5
C6—C7—C2	119.2 (2)	H14A—C14—H14C	109.5
C6—C7—C8	119.1 (2)	H14B—C14—H14C	109.5
C2—C7—C8	121.39 (19)
O2—C1—C2—C3	137.6 (2)	C2—C7—C8—O3	−44.3 (3)
O1—C1—C2—C3	−40.5 (3)	C6—C7—C8—O4	−47.6 (3)
O2—C1—C2—C7	−38.4 (3)	C2—C7—C8—O4	138.6 (2)
O1—C1—C2—C7	143.5 (2)	C10—N2—C9—N3	−178.6 (2)
C7—C2—C3—C4	0.6 (3)	C10—N2—C9—N1	2.5 (3)
C1—C2—C3—C4	−175.4 (2)	C12—N1—C9—N3	178.9 (2)
C2—C3—C4—C5	0.4 (4)	C12—N1—C9—N2	−2.1 (3)
C3—C4—C5—C6	−0.1 (4)	C9—N2—C10—C11	−0.3 (3)
C4—C5—C6—C7	−1.3 (3)	C9—N2—C10—C14	179.6 (2)
C5—C6—C7—C2	2.4 (3)	N2—C10—C11—C12	−2.0 (3)
C5—C6—C7—C8	−171.6 (2)	C14—C10—C11—C12	178.1 (2)
C3—C2—C7—C6	−2.0 (3)	C9—N1—C12—C11	−0.4 (3)
C1—C2—C7—C6	174.0 (2)	C9—N1—C12—C13	178.8 (2)
C3—C2—C7—C8	171.8 (2)	C10—C11—C12—N1	2.3 (3)
C1—C2—C7—C8	−12.2 (3)	C10—C11—C12—C13	−176.8 (2)
C6—C7—C8—O3	129.6 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1	0.82	1.81	2.613 (3)	168
O4—H4···N2^i	0.82	1.84	2.656 (3)	172
N3—H3A···O3^i	0.88 (1)	2.03 (1)	2.890 (3)	166 (2)
N3—H3B···O2	0.89 (2)	1.98 (2)	2.865 (3)	171 (2)

Symmetry code: (i) −x, −y, −z+1.