Hydrochloric Acid → Phenanthren-2-ylboronic acid

Temperature

-60 °C

Under an argon atmosphere, 98 g of 2-iodophenanthrene and 3 L of dehydrated ether were loaded, and then the reaction solution was cooled to −60° C. After that, 210 mL of a 1.6-M solution of n-butyllithium in hexane were added to the reaction solution. The reaction solution was stirred for 1 hour while its temperature was increased to 0° C. The reaction solution was cooled to −60° C. again, and then a solution of 151 g of triisopropyl borate in 100 mL of dehydrated ether was dropped to the reaction solution. The reaction solution was continuously stirred for 5 hours while its temperature was increased to room temperature. Subsequently, 1 L of a 10% aqueous solution of hydrochloric acid was added to the reaction solution, and then the mixture was stirred for 1 hour. The water layer was removed, and the organic layer was washed with water and a saturated salt solution, and was then dried with magnesium sulfate. After magnesium sulfate had been separated by filtration, the organic layer was concentrated. The resultant solid was washed with hexane and toluene. Thus, 42 g of phenanthrene-2-boronic acid as a target were obtained (in 58% yield).

1. temperaturewas increased to 0° C
2. temperatureThe reaction solution was cooled to −60° C. again
3. stirringThe reaction solution was continuously stirred for 5 hours while its temperature
4. temperaturewas increased to room temperature
5. stirringthe mixture was stirred for 1 hour
6. customThe water layer was removed
7. washthe organic layer was washed with water
8. dry with materiala saturated salt solution, and was then dried with magnesium sulfate
9. customAfter magnesium sulfate had been separated by filtration
10. concentrationthe organic layer was concentrated
11. washThe resultant solid was washed with hexane and toluene

ORD record

ord-6f250273fbb744f78defc633a419ca2b

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08822041B2