Efficient Synthesis of New 4-Arylideneimidazolin-5-ones Related to the GFP Chromophore by 2+3 Cyclocondensation of Arylideneimines with Imidate Ylides

A 2+3 condensation of a wide assortment of Schiff bases, prepared from aromatic aldehydes and primary amines, with methyl 2-(1-ethoxyethylideneamino)acetate allows convenient access to an extensive family of substituted 4-arylideneimidazolin-5-one analogues of the green fluorescent protein (GFP) chromophore.