The marine natural products meridianins A and C-E have been synthesized for
the first time starting from the appropriate N-tosyl-3-acetylindole. A fac
ile two-step conversion of N-tosyl-3-acetylindoles to the corresponding mer
idianins by treatment with dimethylformamide dimethylacetal and further cyc
lization of the resulting enaminone with aminoguanidine is described. This
method has also been applied for the preparation of the 3-[(2-amino)pyrimid
in-4-yl]-7-azaindole. (C) 2001 Elsevier Science Ltd. All rights reserved.