5-phenyl-9H-1,3-dioxolo[4,5-h][2,3]benzodiazepin-8(7H)-one

The title compound, C(16)H(12)N(2)O(3), is a novel potent and selective non-competitive antagonist at AMPA/kainate receptors [AMPA is 2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid and kainate is 3-carboxymethyl-4-isopropenylpyrrolidine-2-carboxylic acid]. The crystal structure has been determined at room temperature by X-ray diffraction and the seven-membered ring shows the usual boat conformation. The energy stabilization of the crystal packing of the title compound by significant hydrogen-bond interactions is discussed using theoretical computations.