Benzylation and nitrosation of 4-amino-2-(methylsulfanyl)pyrimidin-6(1H)-one: two P2(1)/c polymorphs of 4-amino-1-benzyl-2-(methylsulfanyl)pyrimidin-6(1H)-one with Z '=1 and 2,4-amino-6-benzyloxy-2-(methylsulfanyl)pyrimidine and 4-amino-1-benzyl-2-(methylsulfanyl)-5-nitrosopyrimidin-6(1H)-one all give different hydrogen-bonded supramolecular structures

4-Amino-1-benzyl-2-(methylsulfanyl)pyrimidin-6(1H)-one, C12H13N3OS, crystallizes in two polymorphic forms, both having space group P2(1)/c, with Z' = 1 for form (I) and Z' = 2 for form (II). In (I), the molecules are linked by a single N-H...O hydrogen bond into simple C(6) chains, which are themselves linked into sheets by aromatic pi-pi interactions, while in (II), chains of edge-fused R-2(4)(8) and R-4(4)(24) rings are generated by four distinct N-H...O hydrogen bonds. In 4-amino-1-benzyl-2-(methylsulfanyl)-5-nitrosopyrimidin-6(1H)-one, C12H12N4O2S, (III), where Z' = 2, two independent three-centre N-H...(N,O) hydrogen bonds generate a C(5) C(6)[ R-1(2)(5)] chain of rings. In 4-amino-6-benzyloxy-2-(methylsulfanyl) pyrimidine, C12H13N3OS, (IV), which is isomeric with (I) and (II), a combination of N-H...N and N-H...O hydrogen bonds generates a sheet of alternating R-2(2)(8) and R-6(6)(28) rings.