The title compound can be synthesized by two routes. Condensation of anthranilic acid (I) with acid chloride (II) provides benzooxazinone (III). Refluxing of (III) with amine (IV) in the presence of p-toluenesulfonic acid yields a mixture of the target quinazolinone and the uncyclized diamide (V), which can be cyclized to the title compound by heating in H2SO4/HOAc.

The anthranilic amide (I) is converted to the corresponding iminophosphorane (II) by treatment with triphenylphosphine, hexachloroethane and triethylamine. Subsequent condensation of (II) with acid chloride (III) gives rise to the desired quinazolinone.