Synthesis of New Benzoxadiazole Compounds Derived from Ethyl-4- (7- Nitro2.1,3,- Benzoxadiazole -4-Yl) Amino Benzoate

Abstract

Refluxing of the 4-chloro –7-nitro- -2,1.3, - benzoxadiazole with ethyl (p-amino) benzoate in absolute ethanol at 78 Co for 12 hrs to give ethyl-4 -(7- nitro-2.1,3,- benzoxadiazole) -4-yl) amino benzoate (1) with 60% yield.Compound (1) was reacted with hydrazine hydrate in absolute ethanol for 5hrs to obtain the carboxylic acid hydrazide (2). The product (2) was treated with phenylisothiocyanat in absolute ethanol to synthesize 2-{4-[(7-nitro-2,1,3-benzoxadiazol-4-yl) amino] benzoyl}-N-phenylhydrazinecarbothioamide (3).Cyclization of the compound (3) using base has afforded 5-{4-[(7-nitro-2,1,3-benzoxadiazol-4-l) amino] phenyl} - 4-phenyl-4H-1,2,4- triazole-3-thiol (4).The synthesized triazoles (4) derivative have been reacted once (alkyl ,aryl halides) and with appropriate secondary amine in dry dioxane to give (alkyl, aryl) thio derivative (5-9) and N-{4-[5-(N,N- substituted)-4-phenyl-4H-1,2,4-triazol-3-yl]phenyl}-7-nitro-2,1,3-benzoxadiazol-4- amine derivatives (11-13). The synthesized compounds have been characterized by their physical and chemical properties, spectral analysis (FT-IR, U.V) in addition to the micro analysis of the elements(C.H.N).