反应详情

Ethyl 3-amino-4-methylaminobenzoate (1.00 g, 5.15 mmol) prepared in the Step 1-1-3 was dissolved in acetic anhydride (4 ml), and the mixture was heated under reflux for 19 hours. After being allowed to cool, the mixture was neutralized with a saturated sodium bicarbonate solution and subjected to extraction with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and then concentrated. The concentrate was purified by silica gel column chromatography (chloroform:methanol=10:1) to give the title compound (1.15 g, quantitative) as a light-brown oily substance.

1. temperaturethe mixture was heated
2. temperatureunder reflux for 19 hours
3. temperatureto cool
4. extractionsubjected to extraction with ethyl acetate
5. dry with materialThe extract was dried over anhydrous magnesium sulfate
6. concentrationconcentrated
7. customThe concentrate was purified by silica gel column chromatography (chloroform:methanol=10:1)