Efficient synthesis of new 1-[alkyl(aryl)]-5-(3,3,3-trihalo-2- oxopropylidene)pyrrolidin-2-ones

Abstract

Reactions of methyl 4-methoxy-6-oxo-7,7,7-trihalo-4-heptenoates 1 and 2 with primary amines RNH2, where R = PhCH2, PhCH 2CH2, Ph, 4-MeC6H4, 4-MeOC 6H4, 4-ClC6H4, 4-BrC 6H4, 2-pyridyl, 5-methyl-3-isoxazolyl, 4-NH 2C6H4 affording methyl 4-[alkyl(aryl)amino]-6- oxo-7,7,7-trihalo-4-heptenoates 3, 4, in good yields (57-95%), which suffer quantitative intramolecular cyclocondensation to produce 1-alkyl(aryl)-5-(2-oxo- 3,3,3-trihalopropylidene)pyrrolidin-2-ones 5, 6, are reported. The structures of the isolated new products were assigned by means of 1H, 13C NMR measurements and mass spectrometry. The Z and E configuration of compounds 3d and 5b respectively were established from X-ray crystallography. ©2008 Sociedade Brasileira de Química.