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 4-(butan-2-ylamino)-5-methyl-2-[(3,4,5-trimethoxyphenyl)methyl]thieno[2,3-d]pyrimidine-6-carbonitrile .
user
C22H26N4O3S
assistant