On triazoles. XL [1]. Non catalytic dehalogenation of some 5-chloro- 1,2,4-triazolo[1,5-a]pyrimidine derivatives

Article abstract of DOI:10.1002/jhet.5570360515

A non catalytic dehalogenation method of type 4 5-chloro-1,2,4- triazolo[1,5-a]pyrimidine derivatives based on the hydrolysis of the corresponding type 5 p-toluenesulphonyl hydrazones with diluted aqueous sodium carbonate solution was elaborated. The method provides the required 5- unsubstituted derivatives 6 also in those cases when the simple hydrogenation is not possible. Using deuterium oxide as the solvent of the hydrolysis, deuterium atoms also could be inserted into position 5 of derivatives 6. Different by-products of the reactions were also isolated, and a possible explanation was given for their formation.