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 dimethyl 8-(3-chlorophenyl)-6,9a-dimethyl-3,4,8,9-tetrahydro-2H-pyrido[2,1-b][1,3]oxazine-7,9-dicarboxylate .
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C20H24ClNO5
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