Reaction #1270938

Reaction equation

2-chloro-3,5-dimethylpyrazine

sodium carbonate

4-phenoxyphenylboronic acid

→

3,5-Dimethyl-2-(4-phenoxyphenyl)pyrazine

Yield 89.0%

Solvents

dichloromethane

water

acetonitrile

water

Conditions

Workup

1. 1
   OtherFirst, into a recovery flask equipped with a reflux pipe
2. 2
   TemperatureHeating
3. 3
   Otherwas performed by microwave irradiation (2.45 GHz, 100 W) of this reaction container for 10 minutes, so that reaction
4. 4
   ExtractionA solution of the obtained extract
5. 5
   Washwas washed with water
6. 6
   Dryingdried over magnesium sulfate
7. 7
   FiltrationAfter the drying, the solution was filtered
8. 8
   workup.DISTILLATIONAfter the solvent of this solution was distilled
9. 9
   Washthe obtained residue was washed with methanol, so that the pyrazine derivative which
10. 10
    Otherthe object of the synthesis, Hdmpoppr
11. 11
    Otherwas obtained (a white powder in a yield of 89%)
12. 12
    OtherNote that a microwave synthesis system (Discover, produced by CEM Corporation)
13. 13
    Otherwas used for the microwave irradiation
14. 14
    OtherThe synthesis scheme of Step 1

Procedure

First, into a recovery flask equipped with a reflux pipe were placed 1.35 g of 2-chloro-3,5-dimethylpyrazine, 2.02 g of 4-phenoxyphenylboronic acid, 1.00 g of sodium carbonate, 0.043 g of bis(triphenylphosphine)palladium(II)dichloride (abbreviation: Pd(PPh3)2Cl2), 15 mL of water, and 15 mL of acetonitrile, and the air inside the flask was replaced with argon. Heating was performed by microwave irradiation (2.45 GHz, 100 W) of this reaction container for 10 minutes, so that reaction occurred. After that, water was added to this reaction solution, and extraction with dichloromethane was carried out. A solution of the obtained extract was washed with water and dried over magnesium sulfate. After the drying, the solution was filtered. After the solvent of this solution was distilled, the obtained residue was washed with methanol, so that the pyrazine derivative which was the object of the synthesis, Hdmpoppr, was obtained (a white powder in a yield of 89%). Note that a microwave synthesis system (Discover, produced by CEM Corporation) was used for the microwave irradiation. The synthesis scheme of Step 1 is illustrated in the following formulae (e).

Source