Enamine rearrangement of pyrimidinium salts Part XI: Novel synthesis of some pyrazolo and triazolopyrimidine derivatives

ABSTRACT

The pyrazolo [1,5-a] pyrimidine derivatives IV and VI underwent pyrimidine ring opening, then recyclized when heated with aqueous alcoholic alkali solution to give the corresponding pyrazolo [3,4-b] pyridine V and VII, respectively. In a similar manner, the triazolo [4,3-a] pyrimidine VIII underwent recyclization to the corresponding triazolo [1,5-a] pyrimidine IX