Crystal structures of 2-[(4,6-di-amino-pyrimidin-2-yl)sulfan-yl]- N -(2,4-di-methyl-phen-yl)acetamide and 2-[(4,6-di-amino-pyrimidin-2-yl)sulfan-yl]- N -(3-meth-oxy-phen-yl)acetamide.

In the title compounds, C ₁₄ H ₁₇ N ₅ OS (I) and C ₁₃ H ₁₅ N ₅ O ₂ S (II), the dihedral angle between the pyrimidine and benzene rings is 58.64 (8)° in (I) and 78.33 (9)° in (II). In both compounds, there is an intra-molecular C-H⋯O hydrogen bond, and in (II) there is also an intra-molecular N-H⋯N hydrogen bond present. In the crystals of both compounds, a pair of N-H⋯N hydrogen bonds links the individual mol-ecules to form inversion dimers with R ₂ ² (8) ring motifs. In (I), the dimers are linked by N-H⋯O and C-H⋯O hydrogen bonds, enclosing R ₂ ¹ (14), R ₂ ¹ (11) and R ₂ ¹ (7) ring motifs, forming layers parallel to the (100) plane. There is also an N-H⋯π inter-action present within the layer. In (II), the inversion dimers are linked by N-H⋯O hydrogen bonds enclosing an R ₄ ⁴ (18) ring motif. The presence of N-H⋯O and C-H⋯O hydrogen bonds generate an R ₂ ¹ (6) ring motif. The combination of these various hydrogen bonds results in the formation of layers parallel to the (1-11) plane.