The asymmetric unit of the title compound, C18H18Cl2N2O2, contains one half of an independent mol­ecule, the other half being generated via a centre of inversion at the mol­ecular centroid. In the crystal structure, mol­ecular chains are formed through non-classical C—H⋯ O hydrogen bonds between an axial H atom of the oxazine ring and the O atom of a neighbouring mol­ecule.