Toluene → p-Chlorophenylboric acid

Temperature

-20 °C

4-Bromochlorobenzene (70.6 g) is added into a four mouth flask connecting with a mechanical stirring apparatus, two constant pressure funnels and a temperature probe. Toluene (588.3 ml) and tetrahydrofuran (THF) (147 ml) are added under stiffing at room temperature under argon, and dissolved to obtain a colorless transparent liquid. Then triisopropyl borate (109.2 ml) and n-butyllithium (176.4 ml, 2.5M in hexane) are respectively added into two constant pressure funnels, and cooled the inner temperature to below −78° C., then n-butyllithium solution is dropped to the flask under controlling a dropping speed to keep the inner temperature below −78° C. After addition, the mixture is kept at the temperature for 1 hour, then triisopropyl borate is dropped into the mixture under the temperature below −78° C., and kept at the temperature for 1 hour after addition, and then the cooling system is removed to naturally warm up to −20° C. HCl solution (360.4 ml, 2.2M) is added to the mixture to warm up to about 10° C., and then placed for layer separation. The aqueous phase is reextracted with toluene (58.8 ml, 2 times). The organic phase is combined together and washed with saturated brine to pH=7 to obtain a colorless transparent liquid, dried with anhydrous sodium sulfate, filtered, and evaporated under reduced pressure to remove most of solvents and the white solid is finally precipitated, filtered to obtain a crystal of 4-chlorophenylboric acid (48 g).

1. customunder stiffing at room temperature under argon
2. dissolutiondissolved
3. customto obtain a colorless transparent liquid
4. temperaturecooled the inner temperature to below −78° C.
5. customthe inner temperature below −78° C
6. additionAfter addition
7. waitkept at the temperature for 1 hour
8. additionafter addition
9. customthe cooling system is removed
10. additionHCl solution (360.4 ml, 2.2M) is added to the mixture
11. temperatureto warm up to about 10° C.
12. customplaced for layer separation
13. washwashed with saturated brine to pH=7
14. customto obtain a colorless transparent liquid
15. dry with materialdried with anhydrous sodium sulfate
16. filtrationfiltered
17. customevaporated under reduced pressure
18. customto remove most of solvents
19. customthe white solid is finally precipitated
20. filtrationfiltered

ORD record

ord-f80adffadbcd41538cfe328bda9f55c1

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08962626B2