反应详情

12 g (63 mmol) of 3,5-dimethoxyaniline hydrochloride and 20 ml (230 mol) of oxalyl chloride were stirred at 165° C. for 30 min. The excess of oxalyl chloride was distilled (the color of the reaction mixture changed from dark-red to green-yellow). The reaction mixture was cooled and methanol was added. The resulting suspension was heated then filtered, washed with methanol and dried to yield 13 g of 4,6-dimethoxyindole-2,3-dione (100% yield).

1. distillationThe excess of oxalyl chloride was distilled (the color of the reaction mixture
2. temperatureThe reaction mixture was cooled
3. additionmethanol was added
4. temperatureThe resulting suspension was heated
5. filtrationthen filtered
6. washwashed with methanol
7. customdried