[Br:1][C:2]1[C:3]([CH3:10])=[CH:4][C:5]([Cl:9])=[N+:6]([O-])[CH:7]=1.[Si]([C:15]#[N:16])(C)(C)C.C(N(CC)CC)C>C(#N)C>[Br:1][C:2]1[C:7]([C:15]#[N:16])=[N:6][C:5]([Cl:9])=[CH:4][C:3]=1[CH3:10]To a solution of 5-bromo-2-chloro-4-methylpyridine 1-oxide (from step 1) (1.0 eq.) in acetonitrile (0.2 M) was added TMSCN (4.0 eq.) and triethylamine (3.0 eq.). The reaction was heated at 100° C. overnight. After cooling to room temperature, the solvent was concentrated en vacuo, and the residue was purified by a COMBIFLASH® system (ISCO) using 0-50% ethyl acetate in hexane to give 3-bromo-6-chloro-4-methylpicolinonitrile.
Wird geladen…