Peptic ulcer is an ulcer of the mucous membrane lining those parts of the alimentary tract exposed to digestive juices or a necrotic lesion characterized by a crater like erosion of the stomach wall (gastric ulcer) or the duodenum (duodenal ulcer) often associated with painful symptoms. Thiazole derivatives have been reported to possess antiulcer activity. With the view to study antiulcer, antibacterial and antitubercular activities, we have synthesized some new thiazole derivatives and screened them for the same. A mixture of 2-hydroxy-1-naphthaldehyde, ethyl bromoacetate and anhydrous potassium carbonate in dry acetone was heated under reflux for 24.35 hours and then filtered which yielded Naphthyl [2,1-b]furan-2-ethyl carboxylate which was mixed with hydrazine hydrate in ethanol and refluxed for 18.3 hours to yield Naphtho [2,1- b]furan-2-carbohydrazide. A solution of various substituted aldehydes in ethanol was added to a solution of naphtho[2,1-b]furan-2-carbohydrazide in DMF, refluxed for 8.2 hours poured into crushed ice and then filtered to give N-[Substituted benzylidene]- naphtho [2,1-b]furan-2- carboxamide which were dissolved in 1,4-dioxan, mercaptoacetic acid and zinc chloride was refluxed for 14.4 hours to yield N-[Substituted phenyl]- 1',3'-thiazol-5-one]-naphtho [2,1- b]furan-2-carboxamide. It was observed that among ten compounds synthesized only three compounds showed potent antiulcer activity. Only four compounds showed significant antibacterial activity. These compounds were further subjected for Antitubercular activity and all the four showed sensitivity at concentrations 50 and 100 μg/ml.