%0 Journal Article
%A Cledera, Pilar
%A Sánchez Cebrián, Juan Domingo
%A Caballero, Esmeralda
%A Yates, Tamara
%A Ramírez,  Elena G.
%A Avendaño López, María Carmen
%A Ramos García, María Teresa
%A Carlos Menéndez
%A Menéndez Ramos, José Carlos
%T Microwave-Assisted, Solvent-Free Synthesis of Several Quinazoline Alkaloid Frameworks
%D 2007
%U https://hdl.handle.net/20.500.14352/133517
%X Microwave irradiation leads to a considerable improvement of the cyclocondensation between anthranilic acid and lactim ethers derived from piperazine-2,5-diones in terms of reaction times, yields, and stereocenter integrity. This reaction has been used to prepare some derivatives of the pyrazino[2,1-b]quinazoline-3,6-dione system present in many quinazoline alkaloids. It could also be applied to the synthesis of compounds containing the complete hexacyclic ring system of the anti-MDR natural product N-acetyl¬ardeemin, and other comprising the pentacyclic framework of circumdatin E. The microwave-assisted reaction was also much better than the thermal one when applied to a bis-lactim ether, leading to the corresponding pentacyclic pyrazino[2,1-b:5,4-b′]diquinazoline-8,16-dione in excellent yield.
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