Synthesis Of Naphthyridinones And Benonaphthyridinones From Heterocyclic Ketene Aminals

Heterocyclic ketene aminals are a kind of compounds with special structure,multi-functional groups and multi-reaction sites,both the nitrogen atom of the secondary amino group and the α-carbon atom can be used as nucleophilic sites,they are often used to synthesize many nitrogen-containing heterocyclic and fused heterocyclic compounds,which are also a kind of very important organic synthesis intermediates.Nitrogen-containing heterocyclic compounds are widely used in materials,pesticides,medicine,etc.A "one pot" route was designed to synthesize naphthyridones and benzonaphthyridones,the main contents are as follows:I.Synthesis of naphthyridones and benzonaphthyridonesHeterocyclic ketene aminals and nicotinate N-oxides or quinoline-3-carboxylate N-oxides were used as substrates,acetonitrile was used as solvent,under the condition of diethyl phosphite,N,N-diisopropyl ethyl amine(DIPEA)and CCl4,C2-H of N-oxides was actived.the α-carbon atom of heterocyclic ketene aminals attacked the C-2 of N-oxides,then intramolecular cyclization took place,yielded naphthyridones or benzonaphthyridones.The structures of the synthesized target products were elucidated by 1H NMR,13C NMR and HRMS.（？）Ⅱ.Pd-C catalytic hydrogenation of naphthyridonesThe pyridine rings of naphthyridones were reduced by hydrogenation with Pd-C as catalyst in the methanol.The synthesized target products were characterized and the structures were confirmed by 1H NMR.13C NMR and HRMS.(?)...