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 (2R)-2-chloro-1-[4-[(2S,6R)-2,6-dimethylmorpholin-4-yl]-2-methyl-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-2-phenylethanone .
user
C22H27ClN4O2
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