You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (2S)-2-amino-5-oxo-5-[3-(5-oxo-7-piperazin-1-yl-[1,3,4]thiadiazolo[3,2-a]pyrimidin-2-yl)anilino]pentanoic acid .
user
C20H23N7O4S
assistant