You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule (7-methyl-4-oxopyrido[1,2-a]pyrimidin-2-yl)methyl 2,5-dimethyl-1-(thiophen-2-ylmethyl)pyrrole-3-carboxylate ?
user
C22H21N3O3S
assistant