[Cl:1][C:2]1[C:6]([C:7]2[CH:8]=[N:9][CH:10]=[CH:11][C:12]=2[CH3:13])=[N:5][S:4][N:3]=1.[Br:14]N1C(=O)CCC1=O.O.C([O-])([O-])=O.[K+].[K+]>ClC(Cl)(Cl)Cl>[Br:14][CH2:13][C:12]1[CH:11]=[CH:10][N:9]=[CH:8][C:7]=1[C:6]1[C:2]([Cl:1])=[N:3][S:4][N:5]=1To a solution of 3-(3-chloro-1,2,5-thiadiazol-4-yl)-4-methylpyridine (0.63 g, 3 mmol) in tetrachloromethane (50 ml) was added under nitrogen, N-bromosuccinimide (0.80 g, 4.5 mmol) and α,α-azoisobutyronitril (80 mg, 0.5 mmol). The reaction mixture was stirred at 75° C. overnight. Water (50 ml) was added and after basifying with K2CO3 the reaction mixture was extracted with methylene chloride (3×100 ml). The organic phases were dried (MgSO4) and evaporated. The residue contained a mixture of starting material, the monobromo and the dibromo product. Separation by column chromatography, eluent: ethyl acetate/methylene chloride: 1/10, gave the title compound in 180 mg (20%) yield.
読み込み中…
