4-[3-(Phen­oxy­meth­yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thia­diazin-6-yl]-3-(p-tol­yl)sydnone

In the title triazolothia­diazine derivative, C(20)H(16)N(6)O(3)S {systematic name: 3-(4-methyl­phen­yl)-4-[3-(phen­oxy­meth­yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thia­diazin-6-yl]-1,2,3-oxadiazol-3-ium-5-olate}, an S(6) ring motif is generated by an intra­molecular C—H⋯O hydrogen bond. The 3,6-dihydro-1,3,4-thia­diazine ring adopts a twist-boat conformation. The dihedral angle between the 1,2,3-oxadiazole and 1,2,4-triazole rings is 46.45 (14)°. The 1,2,3-oxadiazole ring is inclined at dihedral angle of 59.49 (13)° with respect to the benzene ring attached to it. In the crystal structure, inter­molecular C—H⋯O and C—H⋯N hydrogen bonds link neighbouring mol­ecules into two-mol­ecule-thick arrays parallel to the bc plane. A short S⋯O inter­action [2.9565 (19) Å] also occurs.