5,5-Dimethyl-2,2-bis­(pyridin-2-yl)-1,3-diazinane

Ismail Warad; Afaf Alruwaili; Saud I Al-Resayes; M Iqbal Choudhary; Sammer Yousuf

doi:10.1107/S1600536812021629

. 2012 May 19;68(Pt 6):o1786. doi: 10.1107/S1600536812021629

5,5-Dimethyl-2,2-bis(pyridin-2-yl)-1,3-diazinane

Ismail Warad ^a, Afaf Alruwaili ^b, Saud I Al-Resayes ^a, M Iqbal Choudhary ^c,^a, Sammer Yousuf ^c,^*

PMCID: PMC3379365 PMID: 22719563

Abstract

In the molecule of the title compound, C₁₆H₂₀N₄, the 1,3-diazinane ring adopts a chair conformation and the dihedral angle formed by the pyridine rings is 78.64 (8)°. The molecular conformation is stabilized by an intramolecular C—H⋯N hydrogen bond, forming an S(6) ring motif. In the crystal, centrosymmetrically related molecules are linked into dimers by pairs of N—H⋯N hydrogen bonds, generating rings of R ₂ ²(10) graph-set motif.

Related literature

For the structures of related hexahydropyrimidines, see: Al-Resayes (2009 ▶); Song et al. (2010 ▶); Jayaratna & Norman (2010 ▶); Fun & Kia (2008 ▶). For standard bond lengths, see: Allen et al. (1987 ▶). graphic file with name e-68-o1786-scheme1.jpg

Experimental

Crystal data

C₁₆H₂₀N₄
M _r = 268.36
Triclinic,
a = 8.5535 (7) Å
b = 8.7124 (8) Å
c = 11.7241 (10) Å
α = 109.824 (2)°
β = 96.444 (2)°
γ = 109.658 (2)°
V = 748.33 (11) Å³
Z = 2
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 298 K
0.48 × 0.42 × 0.39 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.966, T _max = 0.972
8514 measured reflections
2794 independent reflections
2422 reflections with I > 2σ(I)
R _int = 0.016

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.107
S = 1.05
2794 reflections
191 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); 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, PARST (Nardelli, 1995 ▶) and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812021629/rz2740sup1.cif

e-68-o1786-sup1.cif^{(19.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812021629/rz2740Isup2.hkl

e-68-o1786-Isup2.hkl^{(137.1KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812021629/rz2740Isup3.cml

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N4—H4A⋯N2ⁱ	0.882 (15)	2.469 (15)	3.2048 (14)	141.3 (13)
C4—H4B⋯N2	0.93	2.55	3.187 (2)	126

Open in a new tab

Symmetry code: (i) Inline graphic .

Acknowledgments

IW, AA, SIA-R and MIC are thankful for the finanicial support of the King Saud University, Deanship of Scientific Research, College of Science Research Center for the research project.

supplementary crystallographic information

Comment

Condensation of 1,3-diamines with aldehydes and ketones is a well documented reaction for two potential products, classical Schiff bases and hexahydropyrimidine compounds (Al-Resayes, 2009; Song et al., 2010; Jayaratna, & Norman, 2010; Fun & Kia, 2008). Both of these products are extensively utilized as polydentate ligands to synthesize metal coordination complexes. The title compound was obtained during our attempt to synthesize novel ligands in order to study the coordination chemistry of targeted metals.

In the structure of the title compound (Fig. 1), the two pyridine (N1/C1–C5 and N2/C7–C11) rings are equatorially and axially orientated, respectively, with a dihedral angle of 78.64 (8)° between them. The six membered hexahydropyrimidine ring (N3/N4/C6/C12–C14) adopts a chair conformation, with puckering parameters Q = 0.5384 (14) Å, θ = 5.57 (15)° and φ = 179.9 (15)°. All bond lengths (Allen et al., 1987) and angles are in normal range. The molecular conformation is stabilized by a C4—H4B···N2 intramolecular hydrogen bond (Table 1). In the crystal structure, centrosymmetrically related molecules dimerize via pairs of N4—H4A···N2 intermolecular hydrogen bonds, generating rings of R²₂(10) graph-set motif (Fig. 2).

Experimental

A solution of 2-dipyridlketone (0.5 g, 2.9 mmol) in anhydrous ethanol (15 mL) was mixed with 2,2-dimethyl-1,3-propanediamine (0.22 mL, 3.0 mmoL) and allowed to reflux for about six hours. The resulting mixture was concentrated under reduced pressure and the title compound was precipitated by the addition of 50 mL of ice cool distilled water. The precipitates were filtered off, washed three times with 20 mL of distilled water, recrystallized in ethanol and allowed to stand at room temperature. After three days, colourless crystals suitable for single-crystal X-ray data collection were obtained (0.63 g, yield 87%). All chemicals were purchased from Acros.