3,6-Bis(3,4,5-trimethoxy-phen-yl)-1,2,4-triazolo[3,4-b][1,3,4]thia-diazole.

In the mol-ecule of the title compound, C(21)H(22)N(4)O(6)S, the planar central heterocyclic ring system is oriented with respect to the trimethoxy-phenyl rings at dihedral angles of 2.60 (5) and 3.60 (6)°. Intra-molecular C-H⋯N and C-H⋯S hydrogen bonds result in the formation of planar five- and six-membered rings. In the crystal structure, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules. There is a C-H⋯π contact between a methyl group and a trimethoxy-phenyl ring, and a π-π contact between the central heterocyclic ring system and a trimethoxy-phenyl ring [centroid-centroid distance = 3.640 (1) Å].