Dienophilicity of imidazole in inverse electron demand Diels-Alder reactions. 4. Intermolecular reactions with 1,2,4-triazines.
Intermolecular inverse electron demand cycloadditions of 2-substituted imidazoles with various 1,2,4-triazines produced both imidazo[4,5-c]pyridines (3-deazapurines) and pyrido[3,2-d]pyrimid-4-ones (8-deazapteridines). The product distribution was controlled by reactant substituents and influenced by reaction temperature. A regioselective method for the preparation of 6-unsubstituted 1,2,4-triazines was also developed. By using this route to 8-deazapteridines, a new 8-deazafolate analogue was prepared.
Lahue
Brian R
BR
Department of Chemistry, Boston University, 590 Commonwealth Avenue, Massachusetts 02215, USA.
Wan
Zhao-Kui
ZK
Snyder
John K
JK