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 2-[4-(3-methyl-5-propan-2-yl-1,2-oxazole-4-carbonyl)piperazin-1-yl]pyridine-4-carbonitrile ?
user
C18H21N5O2
assistant