[C:1]([O:5][C:6](=[O:21])[C@@H:7]([N:11]1[C:15]2[CH:16]=[CH:17][CH:18]=[CH:19][C:14]=2[NH:13][C:12]1=[O:20])[CH2:8][CH2:9][CH3:10])([CH3:4])([CH3:3])[CH3:2].C([O-])([O-])=O.[K+].[K+].[I-].C[N+](C)(C)[CH2:31][C:32]1[C:33]2[C:40]([CH3:41])=[CH:39][CH:38]=[CH:37][C:34]=2[S:35][CH:36]=1>CN(C=O)C.C(OCC)(=O)C>[C:1]([O:5][C:6](=[O:21])[C@@H:7]([N:11]1[C:15]2[CH:16]=[CH:17][CH:18]=[CH:19][C:14]=2[N:13]([CH2:31][C:32]2[C:33]3[C:40]([CH3:41])=[CH:39][CH:38]=[CH:37][C:34]=3[S:35][CH:36]=2)[C:12]1=[O:20])[CH2:8][CH2:9][CH3:10])([CH3:2])([CH3:3])[CH3:4]To a solution of (S)-2-(2-Oxo-2,3-dihydro-benzimidazol-1-yl)-pentanoic acid tert-butyl ester (0.1 g, 0.34 mmol) in DMF (2 mL) were added K2CO3 (0.1 g, 0.69 mmol) and trimethyl-(4-methyl-benzo[b]thiophen-3-ylmethyl)-ammonium iodide (0.24 g, 0.69 mmol). The reaction mixture was heated to 80° C. for 5 h. The reaction mixture was then diluted with ethyl acetate and washed with water (×4). The organic phase was dried over Na2SO4 and concentrated. The resulting residue was purified by silica gel prep TLC using 98:2 CH2Cl2:MeOH as an eluent to afford 0.11 g (71%) of the desired product as an oily residue. LCMS (ESMS): m/z 451.33 (M+H+).
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