Preparation of 1,2-and 1,4-dihydro derivatives of 6,7-dimethyl-2,3-diphenylquinoxaline via its dianion formed by reductive metallation

摘要

Treatment of 6,7-dimethyl-2,3-diphenylqui-noxaline with sodium in tetrahydrofuran formed a monomeric dianion.The chemical behavior of this dianion was investigated by a variety of reagents.As the result,alkylation reactions gave 1,2-dihydro derivatives,while acylation reactions occured at Impositions.Annulation of the pyrazine ring system was accomplished by treating the dianion with oligo-methylene dichlorides,C1(CH2)_nC1,n=2-4.