反应详情

To 2.0 g (8.9 mmol) of 5-methyl-7-phenyl-1,2,4triazolo[1,5-a]pyrimidin-2-amine stirring in 25 ml of concentrated hydrochloric acid, 1.2 g (17.4 mmol) of sodium nitrite dissolved in 4.0 ml of water was added dropwise at ambient temperature. After the addition, the reaction suspension was warmed at about 60° 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, m.p. 179°-181° C.

1. additionwas added dropwise at ambient temperature
2. additionAfter the addition
3. temperaturethe reaction suspension was warmed at about 60° for 15 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