ChemInform Abstract: REACTION OF 2‐ARYL‐4‐ARYLIDENE‐2‐OXAZOLIN‐5‐ONES WITH SOME NUCLEOPHILIC REAGENTS

Reaction of unsaturated azlactones with sulfur nucleophiles: some observations

“…2) and a,P-unsaturated acid derivatives (3), was reported to form adducts, but these additions do not seem to have been properly investigated. Compounds la-g can behave as bielectrophiles, undergoing cleavage of the 1,5 bond and (or) involvement of the olefinic centre.…”

“…The condensation of hippuric acid with triethyl orthoformate and benzaldehyde by the Erlenmeyer procedure (1, 7) afforded 4-ethoxymethlene-and 4-benzylidene-2-phenyl-4,Sdihydrooxazol-5-ones ( l a ) and (Id), respectively, the (Z) isomer being the major product (6). The similar acetic anhydride-mediated condensation of hippuric acid with salicylaldehyde produced (8) 3-benzoylaminocoumarin (2a) and (Z)-4-o-acetoxybenzylidene-2-phenyl-4,5-dihydrooxazol-5-one (le). The separation was not only tedious but gave low yields of contaminated compounds.…”