4-[2-[[1-(4-chlorophenyl)-4-oxo-2H-pyrazolo[3,4-d]pyrimidin-6-yl]thio]-1-oxoethyl]-1-piperazinecarboxylic acid ethyl ester
4-[2-[[1-(4-chlorophenyl)-4-oxo-2h-pyrazolo[3,4-d]pyrimidin-6-yl]thio]-1-oxoethyl]-1-piperazinecarboxylic acid ethyl ester