Synthesis and characterizations of some new selenolo[2,3-b]quinoxaline derivatives

In this paper, we present the synthesis of new selenoloquinoxaline derivatives starting from 2-chloroquinoxaline-3-carbonitrile 1 . The compound 1 was subjected to a reaction with selenium metal in the presence of NaBH₄ as a reducing agent in ethanol, under a nitrogen atmosphere. This reaction resulted in the formation of the sodium salt of 3-cyanoquinoxaline-2-selenolate, which was subsequently reacted with α-halogenated carbonyl compounds in situ. This reaction produced a series of newly synthesized 3-aminoselenolo2,3-b]quinoxaline-2-substituents. Ethyl 3-aminoselenolo2,3-b]quinoxaline-2-carboxylate 3a was hydrolyzed by sodium hydroxide to give the corresponding sodium salt 9 . This salt was then refluxed with acetic anhydride to produce oxazinone compound 10 . The reaction of compound 10 with ammonium acetate afforded pyrimidoselenolo2,3-b]quinoxaline derivative 11 . Compound 11 was then chlorinated using phosphorous oxychloride to give the corresponding chlorocompound.