You are a chemist. Now you are given a description of a molecule. Please generate a molecule that meets the description.
system
I need a molecule that meets the following conditions: It belongs to the p2x3 antagonist class of molecules. Please represent the molecule in SMILES.
user
CC(C)n1c(=O)nc(Nc2ccc(OC(F)F)cc2)n(Cc2ccc(Cl)cn2)c1=O
assistant