反应详情

To a solution of 2-methyl-8-nitroquinoxaline (3.50 g) in MeOH (350 mL) was added dropwise a 20% aqueous solution of titanium trichloride (88.64 g) at 0° C. After the addition, the reaction solution was warmed to room temperature, and the mixture was stirred for another hour, and then concentrated under reduced pressure. The resultant was neutralized by addition of an aqueous sodium carbonate solution, and the mixture was extracted five times with ethyl acetate (200 mL). The organic layers were combined, dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (chloroform) to give 2-methyl-8-aminoquinoxaline (2.27 g, 77%) as red oil.

1. additionAfter the addition
2. concentrationconcentrated under reduced pressure
3. additionThe resultant was neutralized by addition of an aqueous sodium carbonate solution
4. extractionthe mixture was extracted five times with ethyl acetate (200 mL)
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by silica gel column chromatography (chloroform)