The title compound, C₁₆H₁₃N₃, isolated from Justicia secunda (Acanthaceae), comprises two molecules (which differ slightly in conformation) in the asymmetric unit of space group P\overline 1. Intermolecular Namino-H...Npyrm interactions (Npyrm is a pyrimidine ring N atom) involve only one of the two donor amino H atoms and pyrimidine N atoms per molecule, forming dimeric units via R²₂(8) rings, with N...N distances of 3.058 (2) and 3.106 (3) Å, and N-H...N angles of 172.7 (18) and 175.8 (17)°. The dimers are linked by C-H...π(arene) contacts, with an H...centroid distance of 2.77 Å and a C-H...centroid angle of 141°.