Abstract
A new series of isoxazolylenamines and substituted isoxazolo[2,3-a]pyrimidinones were prepared via condensation of ethoxymethylenemalonate 2a-d and ethoxymethylenecyanoacetate 2e-h with 3-amino-5-methylisoxazole 1. When reactions were carried out under reflux in xylene, the thermal cyclisation of isoxazolylenamines intermediates 3a-d afforded exclusively the isoxazolo[2,3-a]pyrimidinones 4a-d. All the synthesized compounds were characterized by elemental analysis, MS, IR and NMR spectrometry.