Abstract
The reaction of 2-aminocyclohepta[b]pyrroles with ethyl acetoacetate in phoshoryl chloride–polyphosphoric acid gives 2-methyl-4H-cyclohepta[4,5]pyrrolo[1,2-a]pyrimidin-4-ones. A ring closure of diethyl N-(cyclohepta[b]pyrrol-2-yl)aminomethylenemalonates gives 4-oxo-4H-cyclohepta[4,5]pyrrolo[1,2-a]pyrimidine-3-carboxylates (2) in phosphoryl chloride–polyphosphoric acid or in hot t-butylbenzene, which are deesterified by the treatment with hot hydrobromic acid. Compounds 2 undergo replacement reactions towards some electrophiles at positions C-3, C-11, and C-7 (in that order).