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 (6R,7R,8aR)-6-ethyl-7-(3-oxo-1,4-diazepane-1-carbonyl)-2-(1,3-thiazol-4-ylmethyl)-1,3,6,7,8,8a-hexahydropyrrolo[1,2-a]pyrazin-4-one .
user
C19H27N5O3S
assistant