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: The molecule is a p2x3 antagonist. Please represent the molecule in SMILES.
user
NC(=O)Cn1c(=O)nc(Nc2ccc(Oc3ncccn3)cc2)n(Cc2ccc(Cl)cc2)c1=O
assistant