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 9-(7-but-3-en-2-yloxynaphthalen-2-yl)oxy-3,4-dihydropyrido[2,1-c][1,4]thiazine 2,2-dioxide .
user
C22H21NO4S
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