A Simple Synthesis of 5-Ethoxycarbonyl and Ethyl 3-Benzoyl

Abstract

4-Ethoxycarbonyl-5-phenyl-2,3-dihydrofuran-2,3-dione 1 reacts with aldehydes via the acylketene intermediate 2 giving the 1,3-dioxin-4-ones 3a-e and the 1,4-bis(5-ethoxycarbonyl-4-oxo-6-phenyl-4H-1,3-dioxin-2-yl)benzene 4, and a one step reaction between dibenzoylmethane and oxalylchloride gave 3,5-dibenzoyl-2,6-diphenyl-4-pyrone 7. The reaction of 1 with dibenzoylmethane, a dicarbonyl compound, provided ethyl 3-benzoyl-4-oxo-2,6-diphenylpyran-5-carboxylate derivative 9. Compound 9 was converted into the corresponding ethyl 3-benzoyl-4-hydroxy-2,6-diphenylpyridine-5-carboxylate derivative 10 via its reaction with ammonium hydroxyde solution in 1-butanol.