Crystal structures of N-(4-chlorophenyl)-2-[(4,6-diaminopyrimidin-2-yl)sulfanyl]acetamide and N-(3-chlorophenyl)-2-[(4,6-diaminopyrimidin-2-yl)sulfanyl]acetamide

The title compounds, (I) and (II), are 2-[(diaminopyrimidin-2-yl)sulfanyl]acetamides. The molecules have a folded conformation, with the pyrimidine ring being inclined to the benzene ring by 42.25 (14)° in (I), and by 59.70 (16) and 62.18 (15)° in the two independent molecules of compound (II).

The title compounds, C 12 H 12 ClN 5 OS, (I), and C 12 H 12 ClN 5 OS, (II), are 2-[(diaminopyrimidin-2-yl)sulfanyl]acetamides. Compound (II), crystallizes with two independent molecules (A and B) in the asymmetric unit. In each of the molecules, in both (I) and (II), an intramolecular N-HÁ Á ÁN hydrogen bond forms an S(7) ring motif. The pyrimidine ring is inclined to the benzene ring by 42.25 (14) in (I), and by 59.70 (16) and 62.18 (15) in molecules A and B, respectively, of compound (II). In the crystal of (I), molecules are linked by pairs of N-HÁ Á ÁN hydrogen bonds, forming inversion dimers with an R 2 2 (8) ring motif. The dimers are linked via bifurcated N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds, forming corrugated layers parallel to the ac plane. In the crystal of (II), the A molecules are linked through N-HÁ Á ÁO and N-HÁ Á ÁCl hydrogen bonds, forming layers parallel to (100). The B molecules are also linked by N-HÁ Á ÁO and N-HÁ Á ÁCl hydrogen bonds, also forming layers parallel to (100). The parallel layers of A and B molecules are linked via N-HÁ Á ÁN hydrogen bonds, forming a three-dimensional structure.

Supramolecular features
In the crystal of (I), molecules are linked by pairs of N-HÁ Á ÁN hydrogen bonds, forming inversion dimers with an R 2 2 (8) ring motif (Table 1 and Fig. 4). The dimers are linked by via bifurcated N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds, forming corrugated layers parallel to the ac plane (Table 1 and Fig. 5).
In the crystal of (II), the A molecules are linked through N-HÁ Á ÁO and N-HÁ Á ÁCl hydrogen bonds, forming layers parallel to (100). Likewise the B molecules are also linked by N-HÁ Á ÁO and N-HÁ Á ÁCl hydrogen bonds, forming layers parallel to (100). The parallel layers of A and layers of B molecules are linked via N-HÁ Á ÁN hydrogen bonds, forming a three-dimensional structure (  The molecular structure of the two independent molecules (A and B) of compound (II), with the atom labelling. Displacement ellipsoids are drawn at the 30% probability level. The intramolecular N-HÁ Á ÁN hydrogen bonds are shown as dashed lines (see Table 2).  The molecular structure of compound (I), with the atom labelling. Displacement ellipsoids are drawn at the 30% probability level. The intramolecular N-HÁ Á ÁN hydrogen bond is shown as a dashed lines (see Table 1).  The crystal packing of compound (I) viewed along the a axis. H atoms not involved in hydrogen bonding (see Table 1), have been excluded for clarity.

Compound (I):
To a solution of 4,6-diamino-pyrimidine-2-sulfanyl (0.5 g; 3.52 mmol) in 25 ml of ethanol, was added potassium hydroxide (0.2g; 3.52 mmol) and the mixture was refluxed for 30 min, after which 3.52 mmol of 2-chloro-N-(4-chlorophenyl)acetamide derivative was added and refluxed for 4 h. At the end of the reaction (monitored by TLC), the ethanol was evaporated in vacuo and cold water was added; the precipitate formed was filtered and dried to give compound (I) as a crystalline powder (yield 97%). Colourless block-like crystals were obtained from a solution in methanol and ethyl acetate (1:1) by slow evaporation of the solvents at room temperature.
Compound (II): To a solution of 4,6-diamino-pyrimidine-2-thiol (0.5 g; 3.52 mmol) in 25 ml of ethanol was added potassium hydroxide (0.2g; 3.52 mmol) and the mixture was refluxed for 30 min. Then 3.52 mmol of 2-chloro-N-(3-chlorophenyl)acetamide was added and refluxed for 3 h. At the end of the reaction (monitored by TLC), the ethanol was evaporated in vacuo and cold water was added and the precipitate formed was filtered and dried to give compound (II) as a crystalline powder (yield 92%). Colourless block-like crystals were obtained from a solution in methanol and ethyl acetate (2:1) by slow evaporation of the solvents at room temperature.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 3 For both compounds, data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL2016 (Sheldrick, 2015) and PLATON (Spek, 2009). Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

(II) N-(3-Chlorophenyl)-2-[(4,6-diaminopyrimidin-2-yl)sulfanyl]acetamide
Crystal data where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.42 e Å −3 Δρ min = −0.42 e Å −3 Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq C1 0.43039 (