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 7-N-ethyl-6-nitro-4-N-[(2-thiomorpholin-4-ylphenyl)methyl]quinazoline-4,7-diamine using the IUPAC nomenclature.
user
C21H24N6O2S
assistant