Br[C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([Br:8])[N:3]=1.[Li][CH2:10]CCC.[CH3:14][O:15][CH:16]([O:25][CH3:26])[CH2:17][CH2:18][C:19](N(OC)C)=[O:20]>CCOCC>[CH:7](=[C:2](/[N:3]=[C:4]([Br:8])[CH:5]=[CH2:10])\[C:19](=[O:20])[CH2:18][CH2:17][CH:16]([O:15][CH3:14])[O:25][CH3:26])/[CH3:6]To a suspension of 2,6-dibromopyridine(8.1 g, 34.03 mmol) in 80 mL of ether at −70° C., is added BuLi(12.3 mL, 26.17 mmol, 2.5 M in Hexane) in on portion. After stirring at −70° C. for 5 min, 4,4,N-Trimethoxy-N-methyl-butyramide(5.0 g, 26.17 mmol) is added to the solution dropwise. After stirring at −70° C. for 1.5 hr, the reaction mixture is quenched with 120 mL of water and extracted with 3×130 mL of EtOAc. The combined organic layers is concentrated and purified by chromatography(Hexane/EtOAc:70/30) to give N-[1-Eth-(Z)-ylidene-5,5-dimethoxy-2-oxo-pentyl]-acrylimidoyl bromide(5.96 g, 60.5%) as light yellow liquid. M/Z=288.0
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