Abstract: | The structures of the three title isomers, namely 4‐(2‐methylanilino)pyridine‐3‐sulfonamide, (I), 4‐(3‐methylanilino)pyridine‐3‐sulfonamide, (II), and 4‐(4‐methylanilino)pyridine‐3‐sulfonamide, (III), all C12H13N3O2S, differ in their hydrogen‐bonding arrangements. In all three molecules, the conformation of the 4‐aminopyridine‐3‐sulfonamide moiety is conserved by an intramolecular N—H⋯O hydrogen bond and a C—H⋯O interaction. In the supramolecular structures of all three isomers, similar C(6) chains are formed via intermolecular N—H⋯N hydrogen bonds. N—H⋯O hydrogen bonds lead to C(4) chains in (I), and to R22(8) centrosymmetric dimers in (II) and (III). In each isomer, the overall effect of all hydrogen bonds is to form layer structures. |