You are a chemist. Now you are given a description of a molecule. Please generate a molecule that meets the description.
system
Suppose there is a molecule that meets the following description: It belongs to the p2x3 antagonist class of molecules. Please write the SMILES representation of it.
user
COC1CC(C(C)C)C(OC(CN)C(N)NN)CC1N1CCCC1=O
assistant