Approaches to the Synthesis of 5-Benzylidene-2-imidazolin-4-ones

Abstract

Aromatic aldehydes , but not ketones, can be condensed with glycocyamidine . The corresponding alkylbenzylideneglycocyamidines may be made from glycidic esters by reaction with guanidine, followed by cyclization with acetic anhydride. A number of mono- and di -acetylated derivatives of 6,7-dihydropyrrolo[2,3-c]azepine-4,8(1H,5H)- dione have been prepared, but failed to undergo the Darzens reaction. Bromo- and iodo-2-arylazoimidazoles, protected on nitrogen by the methoxyethoxymethyl group, failed to undergo clean lithiation.