Condensed heteroaromatic ring systems. V Formal synthesis of matrine and related compounds using palladium-catalyzed carbon-carbon bond formations as key reactions.

Abstract

The iodination and subsequent dehydroxychlorination of 1, 6-naphthyridin-5(6H)-one gave 5-chloro-8-iodo-1, 6-naphthyridine, which was converted to the 5-methyoxy derivative. Starting from this compound, didehydromatrine was synthesized by using palladium-catalyzed cross-coupling reactions with ethyl acrylate and 3-butyn-1-ol, as key reactions. Similarly, nordehydro-α-matrinidine was synthesized through four steps from 8-bromo-1, 6-naphthyridine, obtained by the bromination o unsubstituted 1, 6-naphthyridine.