You are a chemist. Now you are given a description of a molecule. Please generate a molecule that meets the description.
system
Generate a molecule that fulfills the requirement: It belongs to the pgd2 receptor antagonist class of molecules.
user
O=C(O)Cc1cccc(Oc2ccc(Br)cc2C[N+]2=CC(c3ccc(Cl)cc3)=CC2=O)c1
assistant