Formation of novel 1,2,3,4-tetrasubstituted 3-pyrrolines via cyclisation of γ-halo-β-ketoesters with aromatic amines and aldehydes

Cyclisation of γ-halo-β-ketoesters with aromatic amines and aldehydes in methanol gave novel polysubstituted 3-pyrroline derivatives. A plausible mechanism for the reaction has been proposed. The structures of 1,2,3,4-tetrasubstituted 3-pyrrolines were confirmed by NMR spectroscopy and X-ray crystallography.