Chemistry of Heterocyclic Compounds.
Латвийский институт органического синтеза Латвийской академии наук / Springer New York Consultants Bureau.
Vol. 22.
1986.
P. 200-205
Previously unknown polynuclear condensed systems with bridgehead nitrogen atoms have been obtained by treating acetylenedicarboxylic ester with pyrido[1,2-a]-benzimidazole and tetrahydropyrido[1,2-a]benzimidazole. © 1986 Plenum Publishing Corporation.