"Synthesis and Biological Evaluation of Some Novel Heterocycles Enclosing Nitrogen Atoms"

Abstract

The Present work aimed to synthesis some novel quinazolinone and fused quinazoline derivatives from the reaction of 3, 1-benzoxazine-3(4H)-one 65 with different nitrogen nucleophiles. The treatment of 65 with methyl glycinate hydrochloride in dry pyridine gave the open chain adduct of methyl acetate derivative 66, while heating benzoxazine-one 65 with hydroxyl amine hydrochloride in dry ethanol and presence of a catalytic amount of freshly fused sodium acetate afforded the cyclic N-hydroxy quinazolinone derivative 67. Heating of benzoxazine-one 65 with cyanoacetohydrazide in ethanol and in the presence of few drops of glacial acetic acid yielded the fused pyrazolo-quinazoline derivative N-acetyl-N-(1-(1-cyano-2-oxo-2,3-dihydropyrazolo[1,5-c]quinazolin-5-yl)-2-(naphthalen-1-yl)vinyl)benzamide(68). Similar treatment of 65 with thiocarbohydrazide afforded the fused 1, 2, 4, 5-tetrazino-quinazoline derivative 69 in a good yield. Refluxing of benzoxazine-one 65 with sodium azide in dry pyridine gave a mixture of 1-(naphthalen-1-yl)-3-oxo-3-(2-oxo-2,3-dihydro-1Hbenzo[d]imidazol-1-yl)prop-1-en-2-yl)acetamide (70) (major) and 2-(5-(1-acetamido-2-(naphthalen-1-yl)vinyl)-1H-tetrazol-1-yl)benzoic acid (71) (minor). The treatment of 65 with hydrazine hydrate in refluxing ethanol afforded the open chain adduct 3-((2-(hydrazinecarbonyl)phenyl)amino)-1-(naphthalen-1-yl)-3-oxoprop-1-en-2-yl)benzamide(72). While, on carrying out the same reaction in an excess of hydrazine hydrate we obtain the cyclized N-amino quinazolinone derivative 73. Fusion of 65 with ammonium acetate or refluxing it in formamide afforded the 4-oxo-3, 4-dihydroquinazolinone derivatives 74.