Synthesis of novel benzo[ h][1,6]naphthyridine derivatives from 4-aminoquinoline and cyclic β-ketoester

Abstract

This paper describes the synthesis of 2,8-dichloroquinolin-4-amine 4 and 4,5,7-trichloro-3-(2-chloroethyl)-2-methylbenzo[ h][1,6]naphthyridine 8 as novel class of building blocks. Also describes the regioselective S NAr reactions of 2,4,8-trichloroquinoline 2 on C 2 and C 4 positions with azide, similarly S NAr reactions of benzo[ h][1,6]naphthyridine 8 at C 4, C 5 positions, and S N2 reactions on C 3-(2-chloroethyl) side chain with nucleophiles such as primary aromatic amines, methoxide/ethoxide, and azide at different temperatures.