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

Abstract 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 NaBH 4 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‐aminoselenolo[2,3‐ b ]quinoxaline‐2‐substituents. Ethyl 3‐aminoselenolo[2,3‐ 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 pyrimidoselenolo[2,3‐b]quinoxaline derivative 11 . Compound 11 was then chlorinated using phosphorous oxychloride to give the corresponding chlorocompound.