Formation of [2 + 2] cycloadducts from heterocyclic formamidines and phenyl isocyanate
Abstract
Heterocyclic formamidines react with phenyl isocyanate at room temperature to give a [2 + 2] cycloadduct which decomposes at elevated temperatures in two different ways; phenyl isocyanate reacts with the heterocyclic isocyanate formed in situ to form a new cycloadduct, a fused 1,3,5-triazine-2,4-dione derivative.