2-Hy­droxy-4-meth­oxy­benzaldehyde thio­semicarbazone

The title Schiff base compound, C(9)H(11)N(3)O(2)S, was prepared by the reaction of equimolar quanti­ties of 2-hy­droxy-4-meth­oxy­benzaldehyde with thio­semicarbazide in methanol. The mol­ecule adopts a trans configuration with respect to the azo­methine group and an intra­molecular O—H⋯N hydrogen bond generates an S(6) ring. In the crystal structure, mol­ecules are linked through inter­molecular N—H⋯O and N—H⋯S hydrogen bonds, forming a three-dimensional network.