Convenient Synthesis of 3-Aminocoumarin Derivatives by the Condensation of 1,4-Diacetyl- or 3-Substituent-2,5-piperazinediones with Various Salicylaldehyde Derivatives

Article abstract of DOI:10.1246/bcsj.59.3917

The condensation of 1,4-diacetyl- or 3-substituted 2,5-piperazinediones (PDO) with various salicylaldehyde derivatives in the presence of a base, such as potassium t-butoxide or triethylamine, was found to give two extremely different kind of products: 1-acetyl-3-arylmethylene-PDO and 3-(acylamino)coumarin derivatives.The former, which has a (Z)-geometric structure, was readily converted to the latter by irradiation.Furthermore, the conversion mechanism and the structural confirmation are discussed.