Base-promoted cyclization of 3-alkynylquinoxaline-2-carbonitriles with CH-acids: a new method for the phenazine ring synthesis
作者:Huong T.L. Nguyen、Anna V. Gulevskaya、Alexander F. Pozharskii、Julia I. Nelina-Nemtseva
DOI:10.1016/j.tet.2014.05.023
日期:2014.8
THF or DMSO. A new cascade process includes nucleophilic addition of a CH-acid carbanion to the CC bond of 3-alkynylquinoxaline-2-carbonitrile, 6-exo-dig cyclization of the intermediateallylcarbanion with the formation of 2,2-disubstituted 1-imino-1,2-dihydrophenazine and its aromatization via elimination of the C(2)-substituent. Several secondary reactions were also disclosed and discussed.