[Cl:1][C:2]1[C:3]([CH3:20])=[C:4]([S:8]([NH:11][C:12]2[S:13][CH:14]=[C:15]([CH2:17][CH2:18]O)[N:16]=2)(=[O:10])=[O:9])[CH:5]=[CH:6][CH:7]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C(Br)(Br)(Br)[Br:41].O>CN(C=O)C>[Br:41][CH2:18][CH2:17][C:15]1[N:16]=[C:12]([NH:11][S:8]([C:4]2[CH:5]=[CH:6][CH:7]=[C:2]([Cl:1])[C:3]=2[CH3:20])(=[O:10])=[O:9])[S:13][CH:14]=1An ice-cold mixture of EXAMPLE 181A (2.03 g, 6.10 mmol), triphenylphosphine (4.80 g, 18.31 mmol) and carbontetrabromide (6.07 g, 18.31 mmol) in DMF (30 mL) was stirred for 1.5 h, and was then poured into water. The mixture was extracted with DCM, dried (sodium sulfate) and the solvent was evaporated. The crude material was twice purified by flash chromatography on silica gel gradient eluting with 0-4% acetone in DCM giving N-[4-(2-bromoethyl)-1,3-thiazol-2-yl]-3-chloro-2-methylbenzenesulfonamide as a solid (990 mg, 41%). MS (Ionspray, [M+H]+) m/z 394; Anal. Calcd. (found) for C12H12BrClN2O2S2: C, 36.4 (36.6)%; H, 3.1 (3.3)%; N ,7.1 (7.2)%.
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