Crystal structure of 4-chloro-2-[(5-eth­oxy-1,3,4-thia­diazol-2-yl)meth­yl]-5-(piperidin-1-yl)pyridazin-3(2H)-one

In the title mol­ecule, C₁₄H₁₈ClN₅O₂S, the six atoms of the 1,6-di­hydro­pyridazine ring are essentially coplanar (r.m.s. deviation = 0.008 Å), and the dihedral angle between this and the 1,3,4-thia­diazole ring is 62.06 (10)°. In the crystal, centrosymmetrically related mol­ecules are linked by inter­molecular C-H-O hydrogen bonding to form a supra­molecular dimer. The terminal ethyl group is statistically disordered over two positions.