A new synthetic approach to condensed 1,2,4-triazines based on using the tandem AN-SNipso and SNH-SNipso reactions has been developed. 5-Methoxy-3-penyl-l,2,4 1,2,4-triazine and its N1-methyl quaternary salt were found to react with C,N-, C,O- and N,N?-bifunctional nucleophiles (m-phenylenediamine, resorcinol, semicarbazide and ureas) into triazacarbazoles, benzofuro[2,3-e][1,2,4]-triazines, and 6-azapurine derivatives. In all cases nucleophiles attack first the unsubstituted C-6 carbon of the triazine ring, while the final stage is replacement of the methoxy group affording cyclization products