Reaction #1885018

Reaction equation

potassium carbonate

2-(4-iodophenyl)benzoxazole

2-bromophenylboronic acid

tri(o-tolyl)phosphine

→

powdery white solid

Yield 29.0%

2-(2′-bromobiphenyl-4-yl)benzoxazole

Yield 29.0%

Solvents

1,2-dimethoxyethane

Conditions

Workup

1. 1
   OtherInto a 100 mL three-neck flask were put
2. 2
   OtherAfter the mixture was degassed under low pressure
3. 3
   workup.ADDITIONAfter the stirring, toluene was added into the mixture
4. 4
   Washthe organic layer was washed with a saturated aqueous solution of sodium carbonate and brine in this order
5. 5
   workup.ADDITIONAfter the washing, magnesium sulfate was added into the organic layer
6. 6
   Otherto dry the organic layer
7. 7
   FiltrationAfter the drying, the mixture was subjected to suction filtration
8. 8
   Otherto give a filtrate
9. 9
   FiltrationThe obtained filtrate was subjected to suction filtration through Celite (manufactured by Wako Pure Chemical Industries, Ltd., Catalog No. 531-16855)
10. 10
    Otherto give a filtrate
11. 11
    ConcentrationThe obtained filtrate was concentrated
12. 12
    Otherpurification by silica gel column chromatography
13. 13
    ConcentrationAn obtained fraction was concentrated
14. 14
    Otherto give a solid
15. 15
    OtherThe obtained solid was recrystallized with a mixed solvent of chloroform and hexane

Procedure

Into a 100 mL three-neck flask were put 7.0 g (22 mmol) of 2-(4-iodophenyl)benzoxazole, 4.4 g (22 mmol) of 2-bromophenylboronic acid, 0.049 g (0.22 mmol) of palladium(II) acetate, and 0.46 g (1.5 mmol) of tri(o-tolyl)phosphine. Into the mixture were added 60 mL of 1,2-dimethoxyethane (DME) and 30 mL of a 2M aqueous solution of potassium carbonate. After the mixture was degassed under low pressure, the atmosphere in the flask was substituted by nitrogen. This mixture was stirred at 90° C. for 10 hours. After the stirring, toluene was added into the mixture and the organic layer was washed with a saturated aqueous solution of sodium carbonate and brine in this order. After the washing, magnesium sulfate was added into the organic layer to dry the organic layer. After the drying, the mixture was subjected to suction filtration to give a filtrate. The obtained filtrate was subjected to suction filtration through Celite (manufactured by Wako Pure Chemical Industries, Ltd., Catalog No. 531-16855) to give a filtrate. The obtained filtrate was concentrated, and purification by silica gel column chromatography was performed. The column chromatography was performed first using a mixed solvent of chloroform and hexane (chloroform:hexane=1:4) as a developing solvent and then using a mixed solvent of chlorofoini and hexane (chloroform:hexane=1:1) as a developing solvent. An obtained fraction was concentrated to give a solid. The obtained solid was recrystallized with a mixed solvent of chloroform and hexane to give 2.2 g of a powdery white solid in a yield of 29%.

Source