[Br:1][C:2]1[CH:3]=[C:4]([S:8]([C:10]2[CH:11]=[C:12]([C:18]#[N:19])[S:13][C:14]=2[N+:15]([O-])=O)=O)[CH:5]=[CH:6][CH:7]=1.CCO>[Fe].C(O)(=O)C>[NH2:15][C:14]1[S:13][C:12]([C:18]#[N:19])=[CH:11][C:10]=1[S:8][C:4]1[CH:5]=[CH:6][CH:7]=[C:2]([Br:1])[CH:3]=14-(3-Bromo-benzenesulfinyl)-5-nitro-thiophene-2-carbonitrile (Example 25: step e; 5.20 g, 15.33 mmol) was dissolved into EtOH (45 mL) and acetic acid (5 mL). The reaction was heated to 50° C. and then iron (4.28 g, 76.69 mmol) was added and the reaction was allowed to heat with stirring overnight. The reaction mixture was filtered through celite which was washed with MeOH and EtOAc to ensure that the product does not remain on the celite. The filtrate was concentrated and then dissolved into EtOAC and washed with brine. The organic layer was dried (MgSO4) and concentrated. The crude reaction mixture was purified by flash column (20% EtOAc in Hexanes) resulting in the desired product as a brown oil (1.5 g, 32%). 1H-NMR (CDCl3): δ 7.38 (1H, s), 7.31-7.29 (1H, m), 7.18 (1H, t, J=1.8, Hz), 7.14 (1H, t, J=7.9 Hz), 6.99-6.96 (1H, m), 5.06 (2H, br s).
Wird geladen…