The syntheses and solid state structures of 3-ethyl-6-methyl-5-alkyl-isocytosines (alkyl= H, Me, Et, n-Pr, n-Bu) are presented. These heterocycles consistently self-assemble into N–H⋯ N hydrogen-bonded dimers, which further associate by N–H⋯ O C interactions, or N–H⋯ O– H⋯ O C hydrogen bonds involving water of crystallization, generating extended supramolecular networks. Crystal packing analysis indicates that although hydrogen ...
