Synthesis of 3-methoxy-2-(1,3,4-oxadiazolyl,1,3,4-thiadiazolyl and 1,2,4- triazolyl)naphtho[2,1-b]furans of biological interest

Sanjeevkumar Giri and K. M. Ba

Abstract

The naphthofuran nucleus [3b] was constructed by refluxingmethyl-2-hydroxy-1-naphthoate [2] and diethyl bromomalonate in presence of dry potassium carbonate. The tautomer product [3a] was ethylated to get a stable 3- methoxy derivative [4]. The compound [4] was converted into 3-methoxynaphtho[2,1-b]furan-2-carbohydrazide[5] by refluxing with 95% hydrazine hydrate in absolute ethanol. The hydrazide [5] was condensed with various isothiocyanates(a-e) to form respective 3-methoxynaphtho[2,1-b]furan-2-carbo(-arylamino)thiosemicarbazides using iodine in potassium iodide, NaOH and H3PO4 gave the title compounds. Newly synthesized compounds were screened for their antibacterial and antifungal activity. Some of them gave encouraging activity.