Synthesis and antioxidant evaluation of some heterocyclic candidates from 3-(1,3-diphenyl-1H-pyrazol-4-yl)-2-(4-oxo-4H-benzo[d][1,3]oxazin-2-yl)propenonitrile

Abstract

A new series of quinazoline derivatives bearing a 1,3-diphenylpyrazole core was synthesized starting from 3-(1,3-diphenyl-1H-pyrazol-4-yl)-2-(4-oxo-4H-benzo[d][1,3]oxazin-2yl)propenonitrile (4) through reactions with some nitrogen nucleophiles. Hydrazinolysis of 4 furnished the biquinazoline and diheterylazine derivatives depending on the reaction conditions. Noteworthy, the benzimidazole derivatives were obtained via treatment with 2-aminoaniline under different reaction conditions. Inspect of the reactions of 4 with hydrazinecarbothioamide and hydrazinecarbothiohydrazide provided thiosemicarbazide, triazepinoquinazoline, and mercaptotetrazine derivatives. The antioxidant screening disclosed that some of these compounds such as 3, 5, 11, 12, and 13 exhibited significant potency.

Graphical Abstract

Keywords:

• Antioxidant
• benzimidazole
• benzoxazinone
• biquinazoline
• propenylamide

Acknowledgment

The authors received no funding for this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).