Mesoionische Sechsringheterocyclen, VI. Umlagerungen von Heterocyclen, IV. Zur thermischen Umlagerung von N-Benzyl-pyrimidinmesoionen./ Mesoionic Sixmembered Heterocycles, VI. Rearrangement Reactions of Heterocycles, IV. Thermal Rearrangement of Mesoionic N-Benzyl-pyrimidines

Abstract

N → O Benzyl group migration upon pyrolysis of the zwitterionic pyrido-pyrimidine (4) leads to the uncharged O-ether (3) in poor yield. On the other hand, heating of the monocyclic mesoionic pyrimidine (12) gives a radicalic N →C migration of the benzyl group yielding the 5,5-dibenzyl-4,6-dioxo-pyrimidine (14).