You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule 1-[4-[1-(4-amino-5,6-dimethylthieno[2,3-d]pyrimidin-2-yl)ethyl]piperazin-1-yl]-2,2-dimethylpropan-1-one ?
user
C19H29N5OS
assistant