反应详情

At 0° C., 10 g (48 mmol) of 3-(2-methyl-6-methylthiophenyl)-4,5-dihydroisoxazole are added a little at a time to 120 ml of conc. sulfuric acid, and the mixture is stirred for about 30 minutes. 3.7 g (23 mmol) of bromine are then added dropwise, and the mixture is stirred at 0° C. for 2.5 hours. The mixture is then allowed to warm to room temperature over a period of about 45 minutes. A homogeneous solution is formed. For work-up, the reaction mixture is poured onto ice-water and extracted three times with methylene chloride. The organic phase is washed with sodium bicarbonate solution, dried with magnesium sulfate and concentrated. This gives 11.4 g of crude product which is used for the next step without further purification.

1. stirringthe mixture is stirred at 0° C. for 2.5 hours
2. customA homogeneous solution is formed
3. additionFor work-up, the reaction mixture is poured onto ice-water
4. extractionextracted three times with methylene chloride
5. washThe organic phase is washed with sodium bicarbonate solution
6. dry with materialdried with magnesium sulfate
7. concentrationconcentrated
8. customThis gives 11.4 g of crude product which is used for the next step without further purification