Fused Tetracyclic Quinoxalines from Reactions of o-Phenylenediamines in Polyphosphoric Acid Academic Article uri icon


  • The condensation of 2,3-diaminobenzoic acid and the 5-chloro derivative with o-hydroxyphenylglyoxylic acid, isatin and benzothiophen-2,3-dione in polyphosphoric acid leads to the appropriate tetracycles. Isomeric products are formed from these unsymmetrical diamines, and methods of assigning particular structures are described.

publication date

  • 1997