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 [4-[(3-fluorophenyl)methyl]piperazin-1-yl]-[4-[(5-methyl-3-nitropyrazol-1-yl)methyl]thiophen-2-yl]methanone using the IUPAC nomenclature.
user
C21H22FN5O3S
assistant