2-Amino-6-meth­oxy-4-(4-methyl­anilino)-5-nitroso­pyrimidine and ethyl N-[4-(adamantan-1-yl­amino)-2-amino-5-nitroso­pyrimidin-6-yl]-3-amino­propionate: polarized electronic structures and hydrogen-bonded supra­molecular assembly in one and two dimensions

In both 2-amino-6-meth­oxy-4-(4-methyl­anilino)-5-nitroso­py­rimidine, C₁₂H₁₃N₅O₂, (I), and ethyl N-[4-(1-adamantylamino)-2-amino-5-nitroso­pyrimidin-6-yl]-3-amino­propionate, C₁₉H₂₈N₆O₃, (II), the nitroso­pyrimidine unit is planar and the bond distances provide evidence for significant polarization of the electronic structures. In (II), the eth­oxy­carbonyl fragment of the mol­ecule is disordered over two sets of sites with occupancies of 0.910 (4) and 0.090 (4). In the mol­ecules of both compounds, there is an intra­molecular N-H...O hydrogen bond. The mol­ecules of (I) are linked into a chain of rings by a combination of N-H...O and C-H...O hydrogen bonds, while the mol­ecules of (II) are linked by a two-centre N-H...N hydrogen bond and a three-centre N-H...(N,O) hydrogen bond to form sheets containing four distinct types of ring.