2-Amino-4-(1-naphthyl)thiazole is a reagent used in the synthesis of 2-substituted ethenesulfonic acid ester derivatives as PTP1B inhibitors. Also used as a reagent in the preparation of pirinixic acid derivatives as dual 5-lipoxygenase and microsomal prostaglandin E2 synthase-1 inhibitors for the treatment of inflammation and various cancers.