An efficient synthesis of benzo[b][1,8]naphthyridine‐3‐carboxylic methyl esters

Methyl‐3‐(2‐chloroquinolin‐3‐yl)acrylates 5a‐i on reaction with methyl amine in acetonitrile yielded methyl‐3‐2‐(methylamino)quinolin‐3‐yl]acrylates 6a‐i . When, these were followed by the reaction with the Vilsmeier reagent, they afforded methyl benzob]1,8]naphthyridin‐3‐carboxylate 7a‐i in good yields.