You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Name the molecular formula for the molecule established as 2,4-dimethoxy-5-[6-methyl-5-[1-(pyridin-2-ylmethyl)pyrrol-3-yl]pyridazin-3-yl]pyrimidine using the IUPAC nomenclature.
user
C21H20N6O2
assistant