1H-Imidazo(1,2-a)(1,4)benzodiazepin-1-one, 6-(2-chlorophenyl)-2,4-dihydro-2-((4-methyl-1-piperazinyl)methylene)-8-nitro-, monomethanesulfonate 61197-73-7 70111-54-5 HR 158 Loprazolam methanesulfonate