12H-[1]Benzopyrano[2,3-b]quinoxalinone synthesis was written by Vinot, Nicole;Maitte, Pierre. And the article was included in Journal of Heterocyclic Chemistry in 1982.Reference of 49679-45-0 This article mentions the following:
3-Benzyl-2-quinoxalinoes (I) were obtained by condensation of o-(H2N)2C6H4 with phenylpyruvic acids. I were easily substituted in position 2, which permitted the preparation of many derivatives; however, cyclization of I into 12H-[1]benzopyrano[2,3-b]quinoxalines failed. This new hetercycle was synthesized from Et-2-phenoxy-3-quinoxalinecarboxylate. In the experiment, the researchers used many compounds, for example, Ethyl 3-chloroquinoxaline-2-carboxylate (cas: 49679-45-0Reference of 49679-45-0).
Ethyl 3-chloroquinoxaline-2-carboxylate (cas: 49679-45-0) belongs to quinoxaline derivatives. Condensed heterocycles of quinoxalines have become attractive targets in synthetic and medicinal chemistry due to their significant biological activities. They are well-known for application in organic light emitting devices, polymers and pharmaceutical agents. The quinoxaline-containing polymers are applicable in optical devices due to their thermal stability and low band gap.Reference of 49679-45-0
Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider