Synthesis of 5-amino-9-benzyl-6-formyl-4-methoxy-2-pivaloylamino-7,8-dihydropyrimido[4,5-b] azepine. A potentially useful intermediate towards the synthesis of pyrimidoazepine based folic acid derivatives

Article abstract of DOI:10.1002/jhet.5570330208

Synthesis of the title compound is described via an intramolecular 1,3-dipolar cycloaddition reaction between the pyrimidine nitrile oxide 24 and an alkyne dipolarophile tethered to the 6-position of the pyrimidine ring. The resulting isoxazolopyrimidoaze