Syntheses of 2-amino-4,6-dichloro-5-nitropyrimidine and 2-amino-4,5,6-trichloropyrimidine: an unusual aromatic substitution

2-Amino-6-hydroxypyrimidine-4(3H)-one

“…The guanine framework was prepared similarly from an intermediate 6, which was prepared by nitration of 3 (eq 8). 15 The imidazole portion was installed in three steps: by Michael addition of an amine, reduction/formylation, and Bischler-Napieralski-type cyclization to afford the target guanine compound. 18…”

A Synthesis of 4-Chloro-2-(trichloromethyl)pyrimidines and Their Study in Nucleophilic Substitution

“…A common problem in the synthesis of these chlorinated heterocycles is how to carry out efficient preparations. 6,7 In this context, cycloaddition reactions employing azadienes in hetero Diels-Alder methodology represents a straightforward and efficient approach for the construction of a wide variety of four-, five-, and six-membered nitrogen-containing heterocycles. [8][9][10][11] Dienes containing two nitrogen atoms have attracted attention in heterocyclic chemistry in recent years because of their importance in the construction of pyrimidines derivatives.…”