You are a chemist. Now you are given a description of a molecule. Please generate a molecule that meets the description.
system
Build a molecule that meets the requirement: It belongs to the p2x3 antagonist class of molecules.
user
CCCCCCn1c(=O)nc(Nc2cccc(C(F)(F)F)c2)n(Cc2ccc(N(C)C)cc2)c1=O
assistant