This compound can be prepared by several related ways: 1) The condensation of N-methyl-2-(4-nitrophenyl)ethylamine (I) with 4-(2-chloroethoxy)nitrobenzene (II) by means of NaI and K2CO3 in refluxing acetonitrile gives 1-(4-nitrophenoxy)-5-(4-nitrophenyl)-3-methyl-3-azapentane (III), which is reduced with H2 over Pd/C in ethanol, yielding the corresponding diamino derivative (IV). Finally, this compound is acylated with methanesulfonyl anhydride in dichloromethane. 2) The condensation of (I) with N-[4-(2-chloroethoxy)phenyl]methanesulfonamide (V) with NaI and K2CO3 as before gives 1-[4-(methanesulfonamide)phenoxy]-3-methyl-5-(4-nitrophenyl)-3-azapentane (VI), which is reduced with H2 over Pd/C as before, yielding the corresponding amino derivative (VII). Finally, this compound is acylated with methanesulfonyl anhydride as usual. 3) The condensation of (II) with N-[4-[2-(methylamino)ethyl]phenyl]methanesulfonamide (VIII) with NaI and K2CO3 as usual gives 1-[4-(methanesulfonamido)phenyl]-3-methyl-5-(4-nitrophenoxy)-3-azapentane (IX), which is reduced with H2 and RaNi to the corresponding amino derivative (X). Finally, this compound is acylated with methanesulfonyl chloride and pyridine. 4) By condensation of N-[4-[2-(methanesulfonyloxy)ethyl]phenyl]methanesulfonamide (XI) with N-[4-[2-(methylamino)ethoxy]phenyl]methanesulfonamide (XII) in refluxing ethanol. 5) By condensation of (V) with (VIII) by means of NaHCO3.