Tris(1,1-dimethylethyl)phosphine → 4,2'-Difluoro-5'-nitrobiphenyl-2-carbonitrile

A mixture of 2-bromo-5-fluorobenzonitrile (20 g, 100 mmol), 2-(2-fluoro-5-nitrophenyl)-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane (from Example B) (34.7 g, 130 mmol) and potassium fluoride (19.2 g, 330 mmol) in tetrahydrofuran (350 ml) and water (20 ml) was degassed with nitrogen for 30 min then treated with tris(dibenzylideneacetone)dipalladium(0) (1.83 g, 2 mmol) followed by tri-tert-butylphosphine (4 ml of a 0.2 M solution in 1,4-dioxane, 0.8 mmol). This mixture was stirred at ambient temperature for 30 min before heating at 50° C. for 18 h. The resulting dark suspension was cooled to ambient temperature, diluted with 0.5 M sodium hydroxide (2.5 l) and stirred at ambient temperature for 4 h. The solid was collected by filtration, washed with water and dried under suction to afford 4,2′-difluoro-5′-nitrobiphenyl-2-carbonitrile as a black solid (28.1 g, >100%) contaminated with dibenzylideneacetone: 1H NMR (360 MHz, CDCl3) δ 7.38-7.56 (4H, m), 8.33-8.40 (2H, m).

1. customwas degassed with nitrogen for 30 min
2. temperaturebefore heating at 50° C. for 18 h
3. temperatureThe resulting dark suspension was cooled to ambient temperature
4. stirringstirred at ambient temperature for 4 h
5. filtrationThe solid was collected by filtration
6. washwashed with water
7. customdried under suction

ORD record

ord-e297d0692ae94dd882d2b5ef5e2c80f7

Source dataset

uspto-grants-2003_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06617326B2