[N:1]([CH2:4][CH2:5][C:6]1[CH:11]=[C:10]([O:12][CH3:13])[CH:9]=[C:8]([O:14][CH3:15])[CH:7]=1)=[C:2]=[S:3].[Cl-].[Cl-].[Cl-].[Al+3]>C(Cl)Cl>[CH3:15][O:14][C:8]1[CH:7]=[C:6]2[C:11](=[C:10]([O:12][CH3:13])[CH:9]=1)[C:2](=[S:3])[NH:1][CH2:4][CH2:5]2To a solution of 245 mg (1.10 mmol) of thioisocyanate 9 in 12 mL of methylene chloride was added 219 mg (1.65 mmol) of aluminum trichloride in one portion at 0° C. After stirring for 2.5 h at room temperature, the reaction mixture was quenched by dropwise addition of water. The layers were separated and the aqueous layer was extracted twice with 10-mL portions of methylene chloride. The combined organic layers were dried (Na2SO4) and concentrated in vacuo. The residue was chromatographed over silica gel (eluted with ethyl acetate) to afford 223 mg (91%) of 10 as a yellow oil: 1H NMR (400 MHz, CDCl3) δ 8.17 (s, 1H), 6.44 (s, 1H), 6.30 (s, 1H), 3.92 (d, J=1.2 Hz, 3H), 3.85 (d, J=1.2 Hz, 3H), 3.40-3.32 (m, 2H), 2.93-2.83 (m, 2H).
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