Novel products arising from bisarylmaleimide synthesis

The reaction of a 2-methoxyarylglyoxalate with a 2,3,6-trifluorophenylacetamide yielded a novel 2-hydroxyaryl substituted bisarylmaleimide (5h). We propose based on X-ray crystallographic evidence that this transformation occurs via formation of a previously undescribed tricyclic ring system (6h). The reactivity of the 2-halo analogues of the arylacetamide (3h) indicated that 2,6-disubstitution facilitated conversion compared to other substitution patterns.