TRIAZOLOPYRIDINES. PART 8. NUCLEOPHILIC SUBSTITUTION REACTIONS OF 5-BROMOTRIAZOLOISOQUINOLINE AND 7-BROMO-TRIAZOLOPYRIDINE

Article abstract of DOI:10.1016/S0040-4020(88)90040-3

Nucleophilic substitution of 5-bromotriazoloisoquinoline (3) and of 7-bromo-3-methyltriazolopyridine (6) proceeds readily to give a range of 5-substituted triazoloisoquinolines (4a)-(4e), and of 7-substituted triazolopyridines (7a)-(7h) respectively.Triazoloisoquinolines have been converted into 1,3-disubstituted isoquinolines (11)-(13), (15), and (16), and triazolopyridines into 2,6-disubstituted pyridines (17)-(19).Of secondary amine nucleophiles, only piperidine reacted with 7-bromo-3-methyl-triazolopyridine (6) to give the 7-substituted derivative (7g).A second product in this reaction was a 2,6-disubstituted pyridine (8); the similar compounds (20)-(24) were the only products when morpholine or N-acetyl-piperazine were used.The reaction between 7-bromotriazolopyridine (9) and piperidine or morpholine gave in high yield the 2,6-disubstituted pyridines (25) and (26).