反应详情

DIEA (11.7 mL, 67.4 mmol) and HBTU (7.03 g, 18.5 mmol) were added to a solution of 6-bromobenzo[d]isothiazole-3-carboxylic acid (4.35 g, 16.9 mmol) and N,O-dimethylhydroxylamine hydrochloride (2.14 g, 21.9 mmol) in DMF (100 mL). The reaction was stirred at room temperature for 2 hours. The mixture was partitioned between water and EtOAc. The organic layer was washed with aqueous NaHCO3 solution and brine, dried and concentrated. The residue was purified by column chromatography (hexane:EtOAc, 3:1) to give 6-bromo-N-methoxy-N-methylbenzo[d]isothiazole-3-carboxamide (4.60 g, 91%) as a solid. 1H NMR (CDCl3, 400 MHz) δ □8.12 (m, 2H), 8.59 (d, J=8.8 Hz, 1H), 3.83 (s, 3H), 3.49 (s, 3H).

1. customThe mixture was partitioned between water and EtOAc
2. washThe organic layer was washed with aqueous NaHCO3 solution and brine
3. customdried
4. concentrationconcentrated
5. customThe residue was purified by column chromatography (hexane:EtOAc, 3:1)