3-[(Furan-2-yl)carbonyl]-1-(pyrimidin-2-yl)thiourea

The title compound, C10H8N4O2S, was synthesized from furoyl isothiocynate and 2-aminopyrimidine in dry acetone. The two N—H groups are in an anti conformation with respect to each other and one N—H group is anti to the C=S group while the other is syn. The amide C=S and the C=O groups are syn to each other. The mean plane of the central thiourea fragment forms dihedral angles of 13.50 (14) and 5.03 (11)° with the furan and pyrimidine rings, respectively. The dihedral angle between the furan and pyrimidine rings is 18.43 (10)°. The molecular conformation is stabilized by an intramolecular N—H⋯N hydrogen bond generating an S(6) ring motif. In the crystal, molecules are linked by pairs of N—H⋯N and weak C—H⋯S hydrogen bonds to form inversion dimers.

The title compound, C 10 H 8 N 4 O 2 S, was synthesized from furoyl isothiocynate and 2-aminopyrimidine in dry acetone. The two N-H groups are in an anti conformation with respect to each other and one N-H group is anti to the C S group while the other is syn. The amide C S and the C O groups are syn to each other. The mean plane of the central thiourea fragment forms dihedral angles of 13.50 (14) and 5.03 (11) with the furan and pyrimidine rings, respectively. The dihedral angle between the furan and pyrimidine rings is 18.43 (10) . The molecular conformation is stabilized by an intramolecular N-HÁ Á ÁN hydrogen bond generating an S(6) ring motif. In the crystal, molecules are linked by pairs of N-HÁ Á ÁN and weak C-HÁ Á ÁS hydrogen bonds to form inversion dimers.
In view of the biological importance of thiourea and its furoic acid derviatives, the structure of the title compound was determined. In the title compound ( Fig. 1), the conformation of the two N-H bonds are anti to each other, and one of them is anti to the C═S and the other is syn in the urea moiety. Furthermore, the amide C═S and the C═O groups are syn to each other, similar to the syn conformation observed in 1-furoyl-3-methyl-3-phenylthiourea (Pérez et al., 2008) and in (Hassan et al., 2007). The bond lengths and angles in the title compound are comparable to other thiourea derivatives (Koch 2001;Pérez et al., 2008;Singh et al., 2012). The C6-S1 and C5-O2 bonds show typical double-bond character. However, the C-N bond lengths, C5-N1, C6-N1, C6-N2 are shorter than the normal C-N single-bond length of about 1.48 Å. These results can be explained by the existence of resonance in this part of the molecule. The central thiourea fragment (O2/C5/N1/C6/N2) makes dihedral angle of 13.50 (14)° with furan ring (O1/C1/C2/C3/C4)and 5.03 (11)° with pyrimidine ring (C7/N3/C8/C9/C10/N4), respectively. The dihedral angle between the mean planes of the furan and pyrimidine rings is 18.43 (10)°. The moleculer geometry is stabilized by an intramolecular N-H···N hydrogen bond generating an S(6) ring motif. In the crystal, molecules are linked by pairs of N-H···N and weak C-H···S hydrogen bonds (Table 1) forming centrosymmetric dimers (Fig. 2).

Experimental
A solution of 2-thiophenecarbonyl chloride (0.01 mol) in anhydrous acetone (80 ml) was added dropwise to a suspension of ammonium thiocyanate (0.01 mol) in anhydrous acetone (50 ml) and the reaction mixture was refluxed for 50 minutes.
After cooling to room temperature, a solution of 4-chloroaniline (0.01 mol) in dry acetone (25 ml) was added and the resulting mixture refluxed for 2 h. The reaction mixture was poured into five times its volume of cold water, upon which the thiourea precipitated. The resulting solide product was crystallized from acetone yielding yellow colour X-ray quality

Computing details
Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO (Agilent, 2011); data reduction: CrysAlis PRO (Agilent, 2011); 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 (Sheldrick, 2008).     4, 158.5, 157.1, 155.4, 147.6, 146.4, 117.6, 117.1, 112.9. 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 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 R-factors(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.