反应详情

Stir a mixture of 4-chlorobenzo[b]thiophene-2-carboxylic acid (0.94 g, 4.44 mmol), N,O-dimethylhydroxylamine hydrochloride (0.86 g, 8.87 mmol), DCC (1.1 g, 5.32 mmol) and DIEA (1.43 g, 1.9 mL, 11.08 mmol) in DCM (8 mL) at ambient temperature for 2 hours. Filter the reaction mixture and the filtrate is washed with brine, dried over anhydrous Na2SO4 and concentrated under vacuum. Purify the residue by column chromatography on silica gel eluting with PE:EtOAc (5:1 to 3:1) to afford 4-chloro-N-methoxy-N-methylbenzo[b]thiophene-2-carboxamide as white solid (0.85 g, 75.2%). 1H NMR (400 MHz, CDCl3) δ 8.10-8.02 (m, 2H), 7.61-7.51 (m, 2H), 3.84-3.79 (s, 3H), 3.37-3.35 (s, 3H).

1. filtrationFilter the reaction mixture
2. washthe filtrate is washed with brine
3. dry with materialdried over anhydrous Na2SO4
4. concentrationconcentrated under vacuum
5. customPurify the residue by column chromatography on silica gel eluting with PE