反应详情

温度

80 °C

15.39 g (66 mmol) of 5,6-dihydroxyisoindoline hydrobromide and 4.48 g (66 mmol) of sodium formate were dissolved in 100 ml of a 50% formic acid aqueous solution, and then 5.17 ml (70 mmol) of 37% formalin was added thereto. The mixture was stirred at 80° C. for 4 hours. Then, the solvent was distilled off under reduced pressure, and the residue was dissolved in 200 ml of water and subjected to active carbon treatment. The active carbon was filtered off, and the filtrate was stirred under cooling with ice, and adjusted to pH 8.0 with a saturated sodium hydrogen carbonate aqueous solution, and then it was stirred at the same temperature for about 30 minutes. The precipitates were collected, and washed with water to obtain yellowish green primary crystalline powder. This powder was combined with secondary crystalline powder obtained from the filtrate, and after an addition of 300 ml of water, stirred for 30 minutes. The insolubles was collected to obtain 7.87 g (yield: 72.3%) of the above identified compound.

1. distillationThen, the solvent was distilled off under reduced pressure
2. dissolutionthe residue was dissolved in 200 ml of water
3. filtrationThe active carbon was filtered off
4. stirringthe filtrate was stirred
5. temperatureunder cooling with ice
6. stirringit was stirred at the same temperature for about 30 minutes
7. customThe precipitates were collected
8. washwashed with water
9. customto obtain yellowish green primary crystalline powder
10. customobtained from the filtrate
11. stirringstirred for 30 minutes
12. customThe insolubles was collected
13. customto obtain 7.87 g (yield: 72.3%) of the