[CH3:1][O:2][C:3]([C:5]1[S:9][C:8]2[C:10]([N+:14]([O-])=O)=[CH:11][CH:12]=[CH:13][C:7]=2[CH:6]=1)=[O:4].[H][H]>CCOC(C)=O.[Pd]>[CH3:1][O:2][C:3]([C:5]1[S:9][C:8]2[C:10]([NH2:14])=[CH:11][CH:12]=[CH:13][C:7]=2[CH:6]=1)=[O:4]7-Nitro-benzo[b]thiophene-2-carboxylic acid methyl ester (1 g, 4.22 mmol) was suspended in EtOAc (40 mL) and a suspension of 10% Pd/C (400 mg) in 20 mL EtOAc was added. Hydrogen gas was introduced into the flask from an H2-filled balloon attached to a needle inserted through a septum. The black suspension was stirred 12 h at room temperature. After stirring 12 h, the black suspension was filtered through diatomaceous earth and the filter cake was washed several times with EtOAc. The combined filtrates were dried (MgSO4), filtered and the solvent was removed to afford 7-amino-benzo[b]thiophene-2-carboxylic acid methyl ester as a yellow solid (860 mg, 100%).
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