o-aminopyridine carboxylic acids, a general synthetic route leading to various pyridopyrimidin-4(3H)-ones is described. The first metallation and functionalization of the pyridine moiety has been studied and a regioselective metallation at the peri-position C5 of the pyridine ring has been highlighted.
synthetic route leading to 4-methoxypyridopyrimidines is described. The first lithiation and functionalization of the pyridine moiety has been studied. According to various structural parameters, the regioselectivity of the metallation is discussed. The functionalization of the 4-methoxypyridopyrimidines via the metallation reaction, provides an efficient process to access new substituted pyridopyrimidines