The title compound, C(15)H(18)N(4)O(3), was formed by the reaction of methanol with 5-ethyl-1,3-dimethyl-alloxazinium perchlorate. Its structure mimics those of possible flavin inter-mediates in flavoenzymes. The heterocyclic rings are substituted with methyl, ethyl and meth-oxy groups. The central tricyclic skeleton is bent due to the presence of an sp(3) C atom. There are weak inter-molecular C-H⋯O inter-actions in the structure, forming a three-dimensional network.