On. Chupakhin et al., A simple one pot synthesis of condensed 1,2,4-triazines by using the tandem A(N)-S-N(ipso) and S-N(H)-S-N(ipso) reactions, J HETERO CH, 38(4), 2001, pp. 901-907
A new synthetic approach to condensed 1,2,4-triazines based on using the ta
ndem A(N)-S-N(ipso) and S-N(H)-S-N(ipso) reactions has been developed. 5-Me
thoxy-3-penyl-1,2,4-triazine and its NI-methyl quaternary salt were found t
o react with C,N-, C,O- and NAP-bifunctional nucleophiles (m-phenylenediami
ne, resorcinol, semicarbazide and ureas) into triazacarbazoles, benzofuro[2
,3-e][1,2,4]-triazines, and 6-azapurine derivatives. In all cases nucleophi
les attack first the unsubstituted C-6 carbon of the triazine ring, while t
he final stage is replacement of the methoxy group affording cyclization pr
oducts.