反应详情

温度

-20 °C

tert-Butyl 2-methyl-4-trifluoromethylphenylcarbamate is prepared in the following manner: 154 ml of a 1.5 M solution of tert-butyllithium in pentane are added dropwise over 1 hour to a solution, kept at −70° C. under an argon atmosphere, of 30 g of tert-butyl 4-trifluoromethylphenylcarbamate in 390 ml of anhydrous tetrahydrofuran. The mixture is stirred for 4 hours at −20° C., cooled to about −70° C., supplemented with 16.4 g of iodomethane and then stirred for 16 hours at a temperature close to 20° C. After hydrolysis with 300 ml of distilled water, the mixture is extracted with twice 160 ml of ethyl acetate in total. The combined organic extracts are dried over magnesium sulphate and concentrated to dryness under reduced pressure (2 kPa). The product obtained is suspended in petroleum ether, separated by filtration, washed with the same solvent and dried under reduced pressure (2 kPa). 20.5 g of tert-butyl 2-methyl-4-trifluoromethylphenylcarbamate are thus obtained in the form of a beige solid melting at 101° C.

1. customtert-Butyl 2-methyl-4-trifluoromethylphenylcarbamate is prepared in the following manner
2. temperaturecooled to about −70° C.
3. stirringstirred for 16 hours at a temperature
4. customclose to 20° C
5. extractionthe mixture is extracted with twice 160 ml of ethyl acetate in total
6. dry with materialThe combined organic extracts are dried over magnesium sulphate
7. concentrationconcentrated to dryness under reduced pressure (2 kPa)
8. customThe product obtained
9. customseparated by filtration
10. washwashed with the same solvent
11. customdried under reduced pressure (2 kPa)