1H-Isoindol-1-one, 3-(diphenylmethylene)-2,3-dihydro-2-methyl-

methyl 2,2''-dimethyl-3,3''-dioxo-2,2',3,3'-tetrahydro-1H-isoindole-1-spiro-2'-[1',4']dithiane-3'-spiro-1''-1''H-isoindole-5'-carboxylate