Carbazole → 9-Naphthalen-2-yl-9H-carbazol

Temperature

5 °C

[PdCl(π-allyl)]2 (5.8 mg, 0.05 mol %) and cBRIDP (22.2 mg, 0.2 mol %) were placed into a 50 mL, two-necked, round bottomed flask equipped a gas inlet, and the flask was evacuated and filled with nitrogen. Subsequently, to the mixture was added dehydrated THF (4.1 mL, 50.5 mmol, 1.6 equivalents) to prepare a catalyst solution. A 200 mL, four-necked, round-bottomed flask equipped with a Teflon® coated magnetic stirring bar, condenser, dropping funnel, thermometer, and a gas inlet was evacuated and filled with nitrogen. Carbazole (5.4 g, 32.5 mmol, 1.03 equivalents) and dehydrated xylenes (33 mL) were charged into the flask, and the mixture was cooled to 5° C. using an ice bath. Subsequently, to the mixture was added a THF solution of MeMgCl (3.22 mol/L, 10.0 mL, 32.2 mmol, 1.02 equivalents) dropwise via the dropping funnel at such a rate that the temperature of the reaction solution was kept at 20° C. or lower, and then the dropping funnel was washed with dehydrated xylenes (6 mL). Subsequently, to the solution were added 2-naphthyl tosylate (9.4 g, 31.6 mmol, 1.0 equivalent) and the catalyst solution (4.1 mL) successively, and the solution was stirred for 15 minutes under reflux. After cooling the reaction mixture to room temperature, to the mixture were added water (100 mL) and ammonium chloride (850 mg). The aqueous layer was separated off, and the organic layer was concentrated under reduced pressure to give solid residue. The residue was dissolved in toluene, and the solution was decolorized by silica gel (500 mg) and filtered through a Celite pad. The filtrate was concentrated under reduced pressure to give the solid, which was recrystallized from toluene/methanol to afford 8.5 g of N-(2-naphthyl)carbazole as a white powder.

1. customtwo-necked, round bottomed flask equipped a gas inlet
2. customthe flask was evacuated
3. additionfilled with nitrogen
4. customto prepare a catalyst solution
5. customthermometer, and a gas inlet was evacuated
6. additionfilled with nitrogen
7. customwas kept at 20° C.
8. washlower, and then the dropping funnel was washed with dehydrated xylenes (6 mL)
9. temperatureunder reflux
10. temperatureAfter cooling the reaction mixture to room temperature
11. customThe aqueous layer was separated off
12. concentrationthe organic layer was concentrated under reduced pressure
13. customto give solid residue
14. filtrationfiltered through a Celite pad
15. concentrationThe filtrate was concentrated under reduced pressure
16. customto give the solid, which
17. customwas recrystallized from toluene/methanol

ORD record

ord-fc65334cd32448f2b11ad54e5d41a2ec

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09233922B2