1H-Benz[e]indole-3-carboxylic acid, 7-[[5-[7-(acetylamino)-1-(chloromethyl)-2,3-dihydro- 5-hydroxy-1H-benz[e]indol-3-yl]-1,5-dioxopentyl]amino]- 1-(chloromethyl)-2,3-dihydro-5-hydroxy-, 1,1-dimethylethyl ester NSC711693