(R)-4-[2-(Methylsulfanyl)pyrimidin-4-yl]-1-(tetrahydrofuran-3-yl)-1H-pyrazol-5-amine

The title compound, C12H15N5OS, was obtained by reaction of 2-(2-(methylthio)pyrimidin-4-yl)-3-oxopropanenitrile with (tetrahydrofuran-3-yl)hydrazine dihydrochloride, and the racemic product was subsequently separated by chiral chromatography (first peak; [α]D 20 = +51.3°). The chiral center at the substituted atom of the tetrahydrofuranyl group has an R-configuration. The pyrimidine and pyrazolyl rings are almost coplanar, their mean planes forming a dihedral angle of 6.4 (1)°. One of the H atoms of the amino group participates in an intramolecular hydrogen bond with the pyrimidine N atom in position 3. The second H atom is involved in an intermolecular hydrogen bond, which links the molecules into an infinite chain.

The title compound, C 12 H 15 N 5 OS, was obtained by reaction of 2-(2-(methylthio)pyrimidin-4-yl)-3-oxopropanenitrile with (tetrahydrofuran-3-yl)hydrazine dihydrochloride, and the racemic product was subsequently separated by chiral chromatography (first peak; [] D 20 = +51.3 ). The chiral center at the substituted atom of the tetrahydrofuranyl group has an R-configuration. The pyrimidine and pyrazolyl rings are almost coplanar, their mean planes forming a dihedral angle of 6.4 (1) . One of the H atoms of the amino group participates in an intramolecular hydrogen bond with the pyrimidine N atom in position 3. The second H atom is involved in an intermolecular hydrogen bond, which links the molecules into an infinite chain.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: TK2382).
The present X-ray study unambiguously established the R configuration of the chiral center at the C3 atom ( Fig. 1).
The pyrimidine and pyrazolyl rings lie approximately in one plane; the dihedral angle formed by their mean planes is equal to 6.4 (1)°. The orientation of the tetrahydrofurane ring can be characterized by the dihedral angle 99.6 (1)° formed by the pyrazolyl plane with the C2-C3-C4 plane.
The molecular geometry of (I) is similar to that of related compound with a methyl substituent at the amino group (Liu et al., 2009). However, the crystal packing is substantially different as (I) has one additional H atom capable of H-bond formation. Indeed, while the H3A atom forms an intramolecular H-bond with the N5 atom of the pyrimidine ring similar to that observed in methyl-substituted structure, the H3B atom is involved in intermolecular H-bonding, which links molecules into infinite chains running along the a axis ( Fig. 2; Table 2).