108775-82-2Relevant academic research and scientific papers
Synthesis of amino derivatives of triazolopyrimidine
Vas'kevich,Savitskii,Zborovskii,Staninets,Rusanov,Chernega
, p. 1403 - 1408 (2007/10/03)
Heterocyclization of 1-(4,6-dimethylpyrimidin-2-yl)-4-R-thiosemicarbazides by the action of methyl iodide in ethanol in the presence of sodium acetate is accompanied by Dimroth rearrangement leading to the formation of 5,7-dimethyl-2-R-amino[1,2,4]triazolo[1,5-a]pyrimidines. Analogous heterocyclization of 4-aryl-1-(4-methyl-6-oxo-1,6-dihydropyrimidin-2-yl) thiosemicarbazides gives 3-arylamino-7-methyl-5-oxo-[1,2,4]triazolo[4,3-a] pyrimidines. The presence in the pyrimidine ring of a carbonyl group capable of forming hydrogen bond with protons of the amino group stabilizes the molecule, thus hampering the Dimroth rearrangement.
Utility of 2-hydrazino-4,6-dimethylpyridine in heterocyclic synthesis
Al-Ashmawy,Abd El-Samii,El Feky,Osman
, p. 110 - 114 (2007/10/03)
2-Hydrazino-4,6-dimethylpyrimidine (1) readily underwent ring closure with benzoyl chloride to give 5,7-dimethyl-3 phenyl- 1,2,4-triazolo[4,3-a]pyrimidine (4a). Either N-benzoyl derivative (2) or the hydrazone (3a) can be used for formation of compound 4a. Reaction of compound 1 with acetylacetone gave the pyrazole derivative (6) rather than 1,2,4-triazepine derivative (5). The pyrrole (9) was the sole product from cyclization of 1 with 2,5 hexanedione. Reaction of compound 1 with carbon disulphide or ethyl chloroformate gave 1,2,4-triazolo[4,3-a]pyrimidines (10 and 12). The reaction of thiosemicarbazides (13 a-c) with ethyl bromoacetate and DCCD was investigated.
