2-[Di(2-chloroethyl)amino]-1-{1-[(3-ethyl-9,10-dimethoxy-1,3,4,6,7,11b-hexa hydro-2H-pyrido[2,1-a]isoquinolin-2-yl)methyl]-6,7-dimethoxy-1,2,3,4-tetrah ydroisoquinolin-2-yl}ethan-1-one