Reaction #2005

Reaction equation

water

2-propanol

4-tolylboronic acid

2-bromo-1-nitrobenzene

→

product

Yield 77.4%

4-Methyl-2'-nitro-1,1'-biphenyl

Yield 77.4%

Solvents

sodium hydroxide

benzene

Conditions

Workup

1. 1
   TemperatureThe two-phase mixture was heated
2. 2
   Temperatureat reflux for three hours
3. 3
   OtherThe cooled reaction mixture
4. 4
   Filtrationwas filtered through Celite
5. 5
   Washthe filter cake washed with fresh benzene
6. 6
   OtherThe organic layer was separated
7. 7
   Washwashed with water (3×)
8. 8
   Dryingdried over magnesium sulfate
9. 9
   Filtrationfiltered
10. 10
    OtherThe filtrate was evaporated under vacuum
11. 11
    Otherthe residue (46.1 g) purified by preparative high pressure liquid chromatography on silica gel
12. 12
    Washeluting with hexane/ethyl acetate (20:1)

Procedure

A vigorously stirred mixture of 34 g (0.25 mol) of 4-tolylboronic acid and 34 g (0.17 mol) of 2-bromo-1-nitrobenzene in a mixture of 170 mL of 5N sodium hydroxide, 57 mL of water, 215 mL of 2-propanol and 1080 mL of benzene was treated with 11.9 g of (tetrakis)triphenylphosphine palladium(0). The two-phase mixture was heated at reflux for three hours. The cooled reaction mixture was filtered through Celite and the filter cake washed with fresh benzene. The organic layer was separated and washed with water (3×), dried over magnesium sulfate and filtered. The filtrate was evaporated under vacuum and the residue (46.1 g) purified by preparative high pressure liquid chromatography on silica gel, eluting with hexane/ethyl acetate (20:1), to give 28.05 g of the product.

Source