The synthesis of aromatic diazatricycles from phenylenediamine-bis(methylene Meldrum's acid) derivatives

Article abstract of DOI:10.1016/S0040-4020(02)01085-2

The thermocyclisation of phenylenediamine-bis(methylene Meldrum's acid) derivatives has been investigated. Those of o-phenylenediamines give 1,10-phenanthroline derivatives, while those of m- and p-phenylenediamines lead to the preferential formation of angular diazatricycles. Thus, for example, the di-Meldrum's acid derivative of 2,5-dichloro-1,4-phenylenediamine gives, via ipso-substitution, the unexpected angular product 19.