Metal/catalyst/alkyne/ alkene‐free one‐pot synthesis of indolizines from 2‐(pyridin‐2‐yl)acetate, DMF‐DMA and α‐halomethylenes

Abstract We have described a simple and robust one‐pot synthesis of 1,3‐disubstitued‐indolizines from 2‐(pyridin‐2‐yl)acetate, DMF‐DMA and α‐halomethylenes without using metal/catalyst/alkyne/alkene. This protocol provides variety of indolizine analogs via in‐situ formed 3‐(dimethylamino)‐2‐(pyridin‐2‐yl)acrylate intermediate, undergoes N‐alkylation followed by Michael addition/cyclization. The gram scale synthesis of indolizine developed by this protocol does not require chromatographic purification. The post synthesis application of alkyne bearing indolizine provided triazole and a beta‐ketoester containing indolizine provided indolizine‐tethered pyrimidine heterocyclic system.