[F:1][C:2]1[CH:10]=[CH:9][C:5]2[O:6][CH2:7][O:8][C:4]=2[C:3]=1[NH2:11].[I:12](Cl)(=O)=O.I(Cl)(=O)=O.C([N+](C)(C)C)C1C=CC=CC=1.C(=O)([O-])[O-].[Ca+2]>ClCCl.CO>[NH2:11][C:3]1[C:4]2[O:8][CH2:7][O:6][C:5]=2[C:9]([I:12])=[CH:10][C:2]=1[F:1]5-Fluoro-1,3-benzodioxol-4-amine (1.1 g, 7.10 mmol), benzyltrimethylammonium dichloroiodate (2.7 g, 7.76 mmol) and calcium carbonate (0.92 g, 9.2 mmol) in a mixture of dichloromethane (10 ml) and methanol (5 ml) were stirred at room temperature for 3 hr. The mixture was filtered through Celite and then evaporated to a dark brown solid. The residue was purified by column chromatography on silica using a 1:1 mixture of methyl tert-butyl ether and iso-hexane as eluent to give 4-amino-5-fluoro-7-iodo-1,3-benzodioxole (1.14 g, 57%) as a pale brown solid; NMR Spectrum: (CDCl3) 3.61 (s, 2H), 6.00 (s, 2H), 6.81 (d, 1H).
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