You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 6-ethyl-2-morpholin-4-yl-N-[(3S,4S)-4-(pyridin-4-ylmethyl)oxolan-3-yl]pyrimidin-4-amine ?
user
C20H27N5O2
assistant