You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[propyl-(2-pyrazin-2-yl-5,6,7,8-tetrahydro-[1]benzothiolo[2,3-d]pyrimidin-4-yl)amino]acetic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H21N5O2S
assistant