AMINO-ACID CONJUGATES OF THE HAPTEN 2-PHENYL-4-ETHOXYMETHYLENE-5(4H)-OXAZOLONE - SYNTHESIS AND CONFIRMATION OF STRUCTURE

2-Phenyl-4-ethoxymethylene-5(4H)-oxazolo (PhOx=CHOEt) was reacted with methylamine, and 2-phenyloxazole-4-carboxylic acid was coupled with methylamine. The spectroscopic properties of the two products were compared in order to confirm that aminolysis of PhOx=CHOEt occurs by displacement of the ethoxy group to give 2-phenyl-4-(substituted-methylene)-5(4H) and not by attack at the ox oxazolone-carbonyl followed by rearrangement to give 2-phenyloxazole-4-carboramides. Ten crystalline conjugates were prepared and characterized by reacting PhOx=CHOEt with an excess of unprotected di- and trifunctional amino acid anions followed by purification by washing them with hydrochloric acid. (C) Munksgaard 1995.