You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-(2,6-dichloro-3,5-dimethoxyphenyl)-4-[2-(dimethylamino)ethylamino]thieno[3,2-d]pyrimidine-7-carboxamide by IUPAC nomenclature, provide its molecular formula.
user
C19H21Cl2N5O3S
assistant