CONVENIENT SYNTHESIS OF 2-AMINO-1,8-NAPHTHYRIDINES, BUILDING-BLOCKS FOR HOST-GUEST AND SELF-ASSEMBLING SYSTEMS

Application of the Reimer-Tiemann reaction to 2,6-diaminopyridine affo rded a 26% yield of 2,6-diaminopyridine-3-carboxaldehyde (4) and a sma ll amount (4%) of 2,6-diaminopyridine-3,5-dicarboxaldehyde. Alternativ ely, conversion of 2,6-diaminopyridine to 2,6-bis(pivaloylamino)pyridi ne (6), directed lithiation with n-butyllithium, treatment with N-form ylmorpholine, and hydrolysis produced 4 in 67% overall yield. The Frie dlander condensation of 4 with a variety of activated and unactivated ketones afforded 2-amino-1,8-naphthyridines and bis(2-amino-1,8-naphth yridines) in moderate to good yields, providing a convenient synthesis of useful building blocks for new host-guest and self-assembling syst ems.