You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 2-tert-butyl-N'-(4-fluorobenzoyl)-4,5-dimethylthieno[2,3-d]pyrimidine-6-carbohydrazide .
user
C20H21FN4O2S
assistant