Application of organolithium and related reagents in synthesis. Part 9. Synthesis and metallation of 4-chloropicolin- and 2-chloroisonicotinanilides. A useful method for preparation of 2,3,4-trisubstituted pyridines

Article abstract of DOI:10.1016/S0040-4020(01)96912-1

The synthesis and metallation (nBuLi) of 4-chloropicolin- and 2-chloroisonicotinanilides (1) and (2) as a way of regiospecific transformation of picolinic and isonicotinic acids into 2,3,4-trisubstituted pyridines (9) and (10), is described. The anilide moiety (masking group) of the formed C³-substituted chloro-anilides (9) and (10) appeared to be effectively removable on acid hydrolysis.