(S)-methyl 4-chloromethyl-6-(5-(7-methoxybenzofuran-2-ylcarbonyl)amino-1H-indol-2-ylcarbonyl)-8-((4-methylpiperazin-1-ylcarbonyl)oxy)-2-trifluoromethyl-1,4,5,6-tetrahydropyrrolo(3,2-e)indole-3-carboxylate hydrochloride