4-Hydrazino-2-(methylsulfanyl)pyrimidine

In the crystal of the title compound, C5H8N4, centrosymmetric dimers are linked by pairs of N—H⋯N hydrogen bonds. Further N—H⋯N links result in a two-dimensional array whereby wave-like supramolecular chains are interconnected by R 2 2(8) ring motifs.

In the crystal of the title compound, C 5 H 8 N 4 , centrosymmetric dimers are linked by pairs of N-HÁ Á ÁN hydrogen bonds. Further N-HÁ Á ÁN links result in a two-dimensional array whereby wave-like supramolecular chains are interconnected by R 2 2 (8) ring motifs.

Comment
Pyrimidines and their derivatives possess biological and pharmacological activities such as antibacterial, antimicrobial, anti-inflammatory, analgesic, anticonvulsant and anti-aggressive activities (Ghorab et al., 2004;Anderson et al., 1990). This prompted us to synthesize compounds bearing the pyrimidine moiety. Hydrazine derivatives are interesting building blocks of heterocyclic compounds containing N-N bonds (Geza et al., 1981;Gante, 1989). Some hydrazine derivatives such as phthalazin-1-yl-hydrazine are widely used as general antihypertensive and vasodilator agents, and are considered as a first-line drug in the management of pregnancy-induced hypertension (Powers et al., 1998;Vidrio et al., 2003). In addition, these compounds are known to decompose easily in the presence of radicals into hydrazine derivatives which are commonly used as rocket fuels. The structure of the title compound, (I), was determined in this context. The molecule of (I), Fig. 1, is essentially planar, with the maximum deviation from the least-squares plane being 0.297 (1) Å for the C5 atom.
The primary interactions in the crystal structure are of the type N-H···N, Table 1 and Fig. 2. Here, molecules form wave-like supramolecular chains along the b axis with successive molecules connected on either side via R 2 2 (8) motifs (Bernstein et al., 1995) to form a 2-D array.
Experimental 4-Chloro-2-(methylsulfanyl)pyrimidine (0.01 mol) was dissolved in methanol and 99% hydrazine hydrate (0.015 mol) was added dropwise with external cooling. The mixture was stirred at room temperature for 5 h. The precipitate was filtered, dried and recrystallized from ethyl acetate. Crystals suitable for X-ray studies are obtained from ethyl acetate by slow evaporation.

Refinement
All H atoms were positioned geometrically and refined with a riding model approximation with C-H = 0.93-0.96 Å, and with U iso (H) = 1.2-1.5U eq (C). The rotating model group was employed for the methyl group. In the case of N3 and N4 atoms, the H atoms were located from a difference Fourier map and refined isotropically, see Table 1 for bond distances. Fig. 1. The molecular structure of (I), showing 50% probability displacement ellipsoids and the atom-numbering scheme.

Figures
supplementary materials sup-2 Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.