XY–ZH Compounds as potential 1,3-Dipoles.: Part 41. Azomethine ylide formation from the reactions of α-amino acids and esters with alloxan (strecker degradation) and with 1-phenyl-3-methylpyrazolin-4,5-dione.

Abstract

In situ formation of imines from α-amino acids and alloxan or pyrazolin-4,5-diones results in decarboxylation forming azomethine ylides which can be trapped as their cycloadducts with maleimides. In the absence of maleimides alloxan gives murexide and the pyrazoline-4,5-diones give rubazonic acid derivatives. The latter are reformulated as stable azomethine ylides. Methyl glycinate reacts with a pyrazolin-4,5-dione and maleimides to give cycloadducts via an ester stabilised azomethine ylide.