A Comparison of Chemical Reactivity in Some Benzo[b]Naphthyridines (Azaacridines)

Abstract

Some comparisons between four series of benzo [b][1,x] naphthyridines (x=5-8) have been made. Bromination in acetic acid gave almost exclusive reaction β to the nitrogen in the outer pyrido ring. Basic silver oxide oxidation of the centre ring occurred in the order x = 6 > 8 > 7 > 5. Methylation occurred on the pyrido nitrogen, the relative nucleophilicities paralleling those of the corresponding naphthyridines . One methiodide (x = 6) underwent an interesting dimerization in solution and the structure of the product was determined by X-ray crystallography.

Naphthyridines. Structure, physicochemical properties and general methods of synthesis

“…These products react with DMSO and trifluoromethanesulfonic anhydride giving rise to S,Sdimethyl-[N(1),N(i )-naphthyridin-2-yl]sulfylimines 64a ± c. 115 The kinetics of N-methylation of benzonaphthyridines 65a ± d with methyl iodide in DMSO have been studied. 117 It was shown that the salt 66, formed from the naphthyridine 65b, slowly dimerises in a 10% aqueous solution of DMSO to give compound 67.…”