Synthesis and transformations of 1-methyl-4-aryl-7-R-isoquinolines

1-Methyl-4-aryl-7-R-isoquinolines were obtained by cyclization of 1,1-diaryl-2-acetamidoethylenes in the presence of phosphorus pentoxide. The condensation of the products with diethyl oxalate leads to the formation of ethyl 1-(4-aryl-7-R-isoquinolyl)pyruvates, which react with o-phenylenediamine to give 1-(4-aryl-7-R-isoquinolyl)-2-[3-(4H)-oxo-2-quinoxalyl]methanes.