You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance ethyl 6-[2-[[(1R)-1-(2-chlorophenyl)ethyl]amino]-2-oxoethyl]sulfanyl-5-cyano-2-methylpyridine-3-carboxylate .
user
C20H20ClN3O3S
assistant