2-Methyl-4,6-bis­(1-methyl­hydrazino)pyrimidine

Daniel J Hutchinson; Lyall R Hanton; Stephen C Moratti

doi:10.1107/S1600536809021643

. 2009 Jun 10;65(Pt 7):o1546. doi: 10.1107/S1600536809021643

2-Methyl-4,6-bis(1-methylhydrazino)pyrimidine

Daniel J Hutchinson ^a, Lyall R Hanton ^a,^*, Stephen C Moratti ^a

PMCID: PMC2969452 PMID: 21582832

Abstract

In the title compound, C₇H₁₄N₆, the amine groups of the two methylhydrazino substituents are orientated in the opposite direction to the methyl substituent at the 2-position of the pyrimidine ring. The molecule is almost planar with only the two amine N atoms lying substantially out of the mean plane of the pyrimidine ring [by 0.1430 (2) and 0.3092 (2) Å]. The H atoms on these amine groups point inwards towards the aromatic ring, such that the lone pair of electrons points outwards from the molecule. Each molecule is linked to two others through N—H⋯N hydrogen bonds between the two amino groups, forming a one-dimensional chain in the [010] direction. Offset face-to-face π–π stacking interactions between the pyrimidine rings organize these chains into a two-dimensional array [centroid–centroid distance = 3.789 (2) Å].

Related literature

For the use of related compounds in the synthesis of molecular strands see: Schmitt et al. (2003 ▶), Schmitt & Lehn (2003 ▶), Gardinier et al. (2000 ▶).

Experimental

Crystal data

C₇H₁₄N₆
M _r = 182.24
Monoclinic,
a = 9.2255 (6) Å
b = 8.5075 (6) Å
c = 12.2323 (7) Å
β = 109.233 (3)°
V = 906.48 (10) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 90 K
0.40 × 0.32 × 0.18 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2006 ▶) T _min = 0.905, T _max = 0.980
16072 measured reflections
1691 independent reflections
1652 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.096
S = 1.04
1691 reflections
133 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: APEX2 (Bruker, 2006 ▶); cell refinement: APEX2 and SAINT (Bruker 2006 ▶); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶) and Mercury (Bruno et al., 2002 ▶); software used to prepare material for publication: SHELXTL and enCIFer (Allen et al., 2004 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809021643/bv2120sup1.cif

e-65-o1546-sup1.cif^{(14.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809021643/bv2120Isup2.hkl

e-65-o1546-Isup2.hkl^{(81.6KB, hkl)}

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
N6—H61⋯N4ⁱ	0.932 (16)	2.177 (17)	3.0933 (18)	167.5 (14)
N4—H4B⋯N2ⁱⁱ	0.909 (16)	2.504 (16)	3.3319 (18)	151.6 (12)
N6—H62⋯N1ⁱⁱ	0.945 (17)	2.418 (17)	3.334 (2)	163.3 (13)
N4—H4A⋯N2ⁱⁱⁱ	0.930 (16)	2.268 (16)	3.1722 (18)	164.2 (13)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

We wish to thank the New Economic Research Fund (grant No UOO-X0808) of the New Zealand Foundation of Research Science and Technology for financial support.

supplementary crystallographic information

Comment

Although 1 is unstable in air, we were able to isolate X-ray quality crystals. Compound 1 was prepared in quantitative yield through the reaction of methylhydrazine and 4,6-dichloro-2-methylpyrimidine under an inert N₂ atmosphere. In 1 the amine groups (N4 and N6) were orientated in the opposite direction to the methyl group (C5). The molecule was planar with only N4 and N6 being out of the mean plane of the pyrimidine ring by 0.1430 (2) and 0.3092 (2) Å, respectively. The hydrogen atoms on these amine groups were located from difference Fourier maps and freely refined. They pointed inwards towards C3 such that the lone pair of electrons on N4 and N6 pointed outwards from the molecule.

Each molecule of 1 was linked to two others through H-bonding between N4 and N6 (Figure 2). The N6—H···N4 distance was measured as 2.177 (16) Å, which corresponded to a N6···N4 distance of 3.093 (2) Å. This H-bond linked molecules of 1 together to form a one dimensional chain in the [0 1 -1] direction. The angle between the planes of adjacent H-bonded molecules was 72.97 (1)°. Offset, face-to-face π-π stacking interactions between the pyrimidine rings organized these chains into a two dimensional array. The centroid to centroid distance for this π-π interaction was 3.789 (2) Å.

Experimental

Under magnetic stirring, 4,6-dichloro-2-methylpyrimidine, (0.4792 g, 2.94 mmol) dissolved in EtOH (30 ml), was added by portions over 20 min to ice cooled methylhydrazine (2.00 ml, 38.0 mmol) flushed with Ar. The mixture was refluxed for 6 h under an inert atmosphere of N₂. After cooling, residual methylhydrazine and EtOH were evaporated, K₂CO₃ (1.025 g) and CHCl₃ (50 ml) were added to the solid residue, and the mixture was stirred for 20 min. The liquid phase was filtered and the solid was washed with more CHCl₃ (50 ml then 30 ml). The combined liquid fractions were evaporated and the resulting solid was dried in vacuo to gave 1 as a white solid (0.5566 g, quant.), unstable in air: ¹H NMR (CDCl₃, 500 MHz) δ/p.p.m.: 5.95 (1H, s, H5), 3.99 (4H, bs, NH₂), 3.22 (6H, s, H8), 2.37 (3H, s, H7). ¹³C NMR (CDCl₃, 500 MHz) δ/p.p.m.: 166.0 (C2), 165.2 (C4, C6), 78.1 (C5), 39.9 (C8), 26.2 (C7). ESMS m/z Found: 365.1063 [2M+H]⁺, 183.1353 [M+H]⁺, 151.0966 [M-(NH₂)₂]⁺. Calc. for C₇H₁₄N₆: [M+H]⁺ 183.1353. Selected IR (KBr disc) ν/cm^-1: 3296 (s, NH str), 3177 (m, CH str), 2933 (m, CH str), 1588 (s, br, NH bend), 1499 (m, pym str), 1399 (m, CH bend), 1136 (w, CN str). Crystals suitable for X-ray determination were grown by slow evaporation of a CDCl₃ solution of 1.