Synthesis, alkylation and ring opening of two differently fused pyridoquinazolones

Alkylation of two differently (linearly and angularly) fused pyridoquinazolones 7 and 10 have been investigated. The linear 7 afforded exclusively N ‐alkyl derivatives 4 , whereas the angular 10 gave both N ‐ and O ‐alkyl products 5 and 11 , respectively depending on the type of the reagent used. Reaction of the new alkylated salts 4, 5 , and 11 with nucleophiles was found strongly dependent on the fusion type of the substrates: the reaction of the linear salt 4 led to opening of the pyrimidine moiety, and the angularly fused salts 5, 11 reacted at the pyridine site to give quinazolyldieneamines 17, 19 . Regioselectivities of the observed conversions were interpreted on FMO basis.