You are a chemist. Now you are given a description of a molecule. Please generate a molecule that meets the description.
system
Come up with a molecule based on the description: The molecule is a endothelin antagonist.
user
COc1cccc(Oc2ccccc2C(=O)NC(C)(COCCO)C(CC(=O)O)NS(=O)(=O)c2ccc(C(C)(C)C)cc2)c1
assistant