2-​Amino-​4-​[4-​(phenylmethyl)​phenyl]​-​3-​thiophenecarboxylic Acid Ethyl Ester is an intermediate in synthesizing Barbadin (B118250), a selective β-arrestin/β2-adaptin inhibitor. It selectively inhibits the interaction between b-arrestin and the b2-adaptin subunit of the clathrin adaptor protein AP2 without affecting the formation of receptor/b-arrestin complexes.