反应详情

5.8 g of carbonyidiimidazole are initially charged in 90 ml of tetrahydrofuran and, a little at a time, admixed with 9 g of 5-(4-trifluoromethyl-3-pyridyl)-1,2,4-oxadiazole-3-carboxylic acid. The mixture is stirred at room temperature for 15 min and then heated at 50° C. for 2 h. After cooling to room temperature, 2.3 g of dimethylamine are introduced in a very gentle gas stream over a period of 2 h. After a reaction time of 12 h, the mixture is concentrated and taken up in 200 ml of diethyl ether. The mixture is washed with ice-cold half conc. hydrochloric acid solution, washed neutral with sat. sodium bicarbonate sol., dried over magnesium sulfate and concentrated under reduced pressure. This gives a slightly yellow oil which solidifies after a number of days to a solid of mp. 52-54° C.

1. temperatureheated at 50° C. for 2 h
2. temperatureAfter cooling to room temperature
3. concentrationAfter a reaction time of 12 h, the mixture is concentrated
4. washThe mixture is washed with ice-cold half conc. hydrochloric acid solution
5. washwashed neutral with sat. sodium bicarbonate sol.
6. dry with materialdried over magnesium sulfate
7. concentrationconcentrated under reduced pressure
8. customThis gives a slightly yellow oil which