反应详情

To 2.0 g (8.9 mmol) of 5-methyl-7-phenyl-1,2,4-triazolo[1,5-a]pyrimidin-2-amine stirring in a mixture of 20 ml of 48% hydrobromic acid and 10 ml of glacial acetic acid, 2.0 g (29.0 mmol) of sodium nitrite was slowly added portionwise with good stirring at ambient temperature. The thick suspension was stirred at about 60° C. for 15 minutes followed by stirring another 10 minutes without heat. Ethyl acetate (150 ml) and excess water were added. The ethyl acetate layer was separated whereby a certain amount of insoluble material present was ignored and the extract washed with water (2X), saturated sodium bicarbonate, brine, dried over magnesium sulfate, and evaporated in vacuo to give a solid residue. Silica gel column chromatography (methylene chloride followed by 10:1 methylene chloride/ethyl acetate) afforded the title compound, 15 m.p. 178°-180° C.

1. additionwas slowly added portionwise
2. stirringThe thick suspension was stirred at about 60° C. for 15 minutes
3. stirringby stirring another 10 minutes
4. temperaturewithout heat
5. customThe ethyl acetate layer was separated whereby a certain amount of insoluble material present
6. washthe extract washed with water (2X), saturated sodium bicarbonate, brine
7. dry with materialdried over magnesium sulfate
8. customevaporated in vacuo
9. customto give a solid residue