Br[C:2]1[N:3]=[CH:4][C:5]([CH3:8])=[N:6][CH:7]=1.[CH2:9](C([Sn])=C(CCCC)CCCC)[CH2:10]CC>CN(C=O)C.C1COCC1.O.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH3:8][C:5]1[CH:4]=[N:3][C:2]([CH:9]=[CH2:10])=[CH:7][N:6]=1
The title compound was prepared by following general procedure 2. 5-Bromo-2-methyl pyrazine (2.0 g, 11 mmol) was dissolved in DMF:THF (3:1, 24 mL). Tributylvinyltin (3.0 g, 12.6 mmol) and Pd(PPh3)4 (0.172 g, 0.143 mmol) was added to this solution at RT under nitrogen and was heated at 100° C. for 3 h. The reaction mixture was cooled to RT and diluted with water (240 mL) and extracted with ethyl acetate (3×150 mL), the combined organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure below 40° C. The crude was purified through column chromatography (2% ethylacetate:hexane in silica 100-200 mesh, Diameter of column—5.0 cm, Height of silica—approx. 5 inch) to provide 2-methyl-5-vinylpyrazine as a light yellow oil (1.0 g, 71% yield).
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