Reaction #40938

Reaction equation

2,4-Di-tert-butoxy-pyrimidine-5-boronic acid

2-bromo-3-methylthiophene

Na2CO3

PPh3

→

title compound

Yield 32.0%

2,4-Di-tert-butoxy-5-(3-methyl-thiophen-2-yl)-pyrimidine

Yield 32.0%

Solvents

n-PrOH

Conditions

Workup

1. 1
   Temperatureat reflux for 2.5 hours
2. 2
   OtherThe solvent was evaporated
3. 3
   workup.DISSOLUTIONthe crude was dissolved in water
4. 4
   Extractionextracted with Et2O
5. 5
   DryingThe organic phase was dried (Na2SO4)
6. 6
   Otherevaporated
7. 7
   OtherThe crude was purified by flash chromatography with ethyl acetate-petroleum ether (1-99)

Procedure

2,4-Di-tert-butoxy-pyrimidine-5-boronic acid (500 mg, 1.75 mmol) was dissolved in n-PrOH (5 mL) and then 2-bromo-3-methylthiophene (236 μl, 2.1 mmol), Na2CO3 (556 mg, 5.25 mmol), PPh3 (133 mg, 0.52 mmol) and Pd(OAc)2 (40 mg, 0.17 mmol) were added. The suspension was stirred at reflux for 2.5 hours. The solvent was evaporated and the crude was dissolved in water and extracted with Et2O. The organic phase was dried (Na2SO4) and evaporated. The crude was purified by flash chromatography with ethyl acetate-petroleum ether (1-99) to give 170 mg of the title compound as a white solid (32% yield).

Source