2,2,6,6-Tetramethylpiperidine → 3-Chloro-2,6-difluoro-4-methoxyphenylboronic Acid

Temperatur

-10 °C

5.1 g of 2,2,6,6-tetramethylpiperidine were dissolved using 200 ml of anhydrous THF. 12.4 ml of a 2.7M solution of n-butyllithium in heptane were added at −10° C. and the mixture was stirred for 10 minutes at −10° C. The mixture was then cooled to −70° C. and a solution of 5.0 g 2-chloro-3,5-difluoroanisole in 40 ml of anhydrous THF added dropwise at −70° C. Stirring was continued for 1 h at −75° C. Then, 7.9 g of triisopropyl borat were added and the mixture was allowed to warm to room temperature. Stirring was continued for 1 h at room temperature. Then, the reaction mixture was poured into 200 ml of a saturated aqueous NaHSO4-solution and extracted twice using 100 ml EA each. The organic layer was washed using 100 ml of a saturated aqueous NaHSO4-solution, dried using MgSO4 and evaporated to yield 5.6 g of the title compound that was used without further purification.

1. temperatureThe mixture was then cooled to −70° C.
2. stirringStirring
3. waitwas continued for 1 h at −75° C
4. temperatureto warm to room temperature
5. stirringStirring
6. waitwas continued for 1 h at room temperature
7. extractionextracted twice
8. washThe organic layer was washed
9. customdried
10. customevaporated

ORD-Eintrag

ord-186ad29d217a439a9f83be1f4d2638ce

Quelldatensatz

uspto-grants-2015_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09018383B2