5-Amino-4-(4-cyclopropylnaphthalen-1-yl)-4H-1,2,4-triazole-3-thiol is a derivative of 5-Amino-4-(4-cyclopropyl-1-naphthalenyl)-2,4-dihydro-3H-1,2,4-Triazol-3-one (A602165), which is an impurity of the drug Lesinuard (L329700), which is used to synthesize febuxostat, a non-purine analog inhibitor of xanthine oxidase. Febuxostat is approved by the European Medicines Agency and the US Food and Drug Administration for treating gout. Molecular Formula: C15H14N4S Molecular Weight: 282.36