Graphene oxide-supported ionic liquid phase catalyst ([GrFemBenzImi]OH) has been prepared by covalent grafting of 1-N-ferrocenylmethyl benzimidazole in the matrix of functionalized graphene oxide followed by anion metathesis reaction. [GrFemBenzImi]OH has been characterized by fourier transform infrared (FT-IR) spectroscopy, fourier transform Raman (FT-Raman spectroscopy), CP-MAS C-13 NMR spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) surface area. [GrFemBenzImi]OH served as a robust heterogeneous catalyst for the synthesis of bioactive 3,4-dihydro-2H-naphtho[2,3-e][1,3]oxazine-5,10-diones by reaction of formaldehyde, 2-hydroxy-1,4-naphthoquinone with structurally diverse aromatic anilines. Recyclability experiments were executed successfully for six consecutive runs. [GRAPHICS] .