[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([C:8](=O)[CH3:9])=[CH:4][C:3]=1[N+:11]([O-:13])=[O:12].[CH3:14][C:15]([S:18]([NH2:20])=[O:19])([CH3:17])[CH3:16].[B-].[Na+]>C1COCC1.[O-]CC.[Ti+4].[O-]CC.[O-]CC.[O-]CC>[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]([NH:20][S:18]([C:15]([CH3:17])([CH3:16])[CH3:14])=[O:19])[CH3:9])=[CH:4][C:3]=1[N+:11]([O-:13])=[O:12]A mixture of 1-(4-amino-3-nitrophenyl)ethanone (500 mg, 2.78 mmol, J. Med. Chem. 1998, 41, 1777-1788), 2-methylpropane-2-sulfinamide (674 mg, 5.56 mmol) in THF (25 mL) was added titanium(IV) ethoxide (1.75 ml, 8.34 mmol) at room temperature. The mixture was stirred at 80° C. for 24 hours. After cooling to room temperature, sodium borohydrate (316 mg, 8.34 mmol) was added to the mixture at room temperature. The mixture was stirred at room temperature for 14 hours. The mixture was quenched with MeOH (6 ml), poured into saturated sodium hydrogencarbonate aqueous solution (20 mL), extracted with EtOAc (150 mL×2). The combined organic layer was washed with brine (50 mL), dried over sodium sulfate and concentrated. The residue was chromatgraphed on a column of silica gel with hexane-EtOAc (1:2) as an eluent to afford 675 mg (85%) of title compound as a yellow solid. 1H NMR (300 MHz, DMSO-d6) δ 1.11 (9H, s), 1.37 (3H, d, J=6.6 Hz), 4.33-4.24 (1H, m), 5.64 (1H, d, J=6.6 Hz), 6.99 (1H, d, J=8.8 Hz), 7.40 (2H, s), 7.45 (1H, d, J=8.8 Hz), 7.97 (1H, s). MS (ESI) m/z 286 (M+H)+, 284 (M−H)−.
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