1-(2,4,6-Trioxo-1,3-diazinan-5-yl­idene)thio­semicarbazide

The title mol­ecule, C₅H₅N₅O₃S, is approximately planar, with a maximum deviation from the mean plane through the non-H atoms of 0.182 (3) Å for the amine N atom. In the crystal, mol­ecules are connected via N—H...O and N—H...S inter­actions, building a three-dimensional hydrogen-bonded network. Additionally, a weak intra­molecular N—H...O hydrogen bond is observed.