You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule 3-(2-methoxyphenyl)-1-[(5S)-5-methyl-3-propan-2-yl-6,8-dihydro-5H-[1,2,4]triazolo[4,3-a]pyrazin-7-yl]propan-1-one ?
user
C19H26N4O2
assistant