Sulfuric Acid → 3-Cyanophenylboronic acid

Temperature

-78 °C

20 g of 3-bromobenzonitrile was dissolved in 100 ml of dry THF and, under a nitrogen atmosphere, 37.6 ml of triisopropoxyborane was added. This solution was cooled to −78° C., and 98.3 ml of 1.6M n-butyllithium hexane solution was dropped for 30 min. with stirring. After stirring at room temperature for 30 min., it was cooled to 0° C., 220 ml of 4M sulfuric acid was added. This solution was refluxed with heating overnight, and then cooled to 0° C. again. 340 ml of 5M sodium hydroxide was added, and extracted with 200 ml of diethyl ether. The aqueous layer was removed, and 6M hydrochloric acid was added until the pH was 2. It was extracted twice with 300 ml of ethyl acetate, dried with magnesium sulfate, and then the solvent was removed. The resulting crude product was recrystallized from DMF-water to produce 11.6 g (72%) of the title compound as acicular light-yellow crystals.

1. stirringAfter stirring at room temperature for 30 min.
2. temperatureit was cooled to 0° C.
3. temperatureThis solution was refluxed
4. temperaturewith heating overnight
5. temperaturecooled to 0° C. again
6. extractionextracted with 200 ml of diethyl ether
7. customThe aqueous layer was removed
8. addition6M hydrochloric acid was added until the pH was 2
9. extractionIt was extracted twice with 300 ml of ethyl acetate
10. dry with materialdried with magnesium sulfate
11. customthe solvent was removed
12. customThe resulting crude product was recrystallized from DMF-water

ORD record

ord-5c61d4d5f156491f8e664b72656fd706

Source dataset

uspto-grants-2004_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06706745B1