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 3-amino-N-[3-(4-aminobutylamino)propyl]-2-oxo-1-(4-phenyl-2,3-dihydro-1,4-benzoxazin-6-yl)thieno[2,3-b]pyrazine-6-carboxamide .
user
C28H33N7O3S
assistant