反应详情

First, in a nitrogen atmosphere, 50 mL of a dibutylether solution containing phenyl lithium (produced by Wako Pure Chemical Industries, Ltd, 2.1 mol/L) and 250 mL of diethyl ether were mixed. Then, 10.33 g of 2,6-dimethylpyrazine was added into this solution while the solution was being cooled with ice, and stirred at a room temperature for 24 hours. Water was added into this mixture and an organic layer was extracted with diethylether. The obtained organic layer was washed with water and dried with magnesium sulfate. After the drying, the solution was filtrated. After the solvent of the filtrate was distilled off, the obtained residue was purified by silicagel column chromatography using dichloromethane as a developing solvent, thereby obtaining an objective pyrazine derivative Hmppr-Me (reddish brown liquid, yield: 16%). A synthesis scheme of Step 1 is shown by the following (a-2).

1. additionwere mixed
2. temperaturewas being cooled with ice
3. extractionan organic layer was extracted with diethylether
4. washThe obtained organic layer was washed with water
5. dry with materialdried with magnesium sulfate
6. filtrationAfter the drying, the solution was filtrated
7. distillationAfter the solvent of the filtrate was distilled off
8. customthe obtained residue was purified by silicagel column chromatography