Diquaternary salts of 1,5- and 1,8-naphthyridines and the structure of their derived pseudo-bases
Abstract
1,5-Naphthyridine and 1,8-naphthyridine react with dimethyl sulphate and with ethylene dibromide, respectively, to form 1,5-dimethyl-1,5-naphthyridinedi-ium dimethosulphate and 5,6-dihydroimidazo[1,2,3-ij][1,8]naphthyridinedi-ium dibromide. The salts readily form pseudo-bases. The salt from 1,5-naphthyridine is reduced by a one-electron transfer to give a relatively stable green radical cation.