Synthesen von Heterocyclen, CC Reaktionen mit cyclischen Oxalylverbindungen, XVIII Zur Reaktion von 4-Benzoyl-5-phenyl-2,3-dihydrofuran-2,3-dion mit Η-aktiven Nucleophilen. / Syntheses of Heterocycles, CC Reactions of Cyclic Oxalyl Compounds, XVIII The Reaction of 4-Benzoyl-5-phenyl-2,3-dihydrofuran-2,3-dione with Η-active Nucleophiles

Abstract

Hydrolysis of 4-Benzoyl-5-phenyl-2,3-dihydrofuran-2,3-dione (1) in water (ethanol) gives dibenzoylmethane and oxalic acid (ethyl ester). 1 reacts with aniline or p-toluidine yielding the 2-pyrrolones (2), which on the other hand are synthesized by addition of the corresponding anilines to the pyrrol-2,3-diones (8). 3 a adds methanol to give the 2-pyrrolone (4), which with aniline can be converted into 2 a. 2 a, b show fragmentation to oxalic acid anilides by heating (2 b) or treating with diazomethane (2 a). The reaction of 1 with p-nitroaniline leads via the furanone-derivative 6 to oxalic acid-di-p-nitroanilide. 1 and N-methylaniline combine to acrylic acid-N-methylanilide (7), which by heating gives the dibenzoyl acetic acid-N-methylanilide