反应详情

Ethyl 3-amino-4-piperidin-1-ylbenzoate (5.38 g, 21.7 mmol) prepared in the Step 3-1-2 was dissolved in formic acid (90%, 40 ml). Hydrogen peroxide solution (20 ml) was added to the solution, and the mixture was heated under reflux for 40 minutes. After being allowed to cool, the mixture was neutralized with a saturated sodium bicarbonate solution and a 25% ammonia water and subjected to extraction with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and then concentrated. The residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=1:1) to give the title compound (3.94 g, 74%) as a light-brown powder.

1. temperaturethe mixture was heated
2. temperatureunder reflux for 40 minutes
3. temperatureto cool
4. extractiona 25% ammonia water and subjected to extraction with ethyl acetate
5. dry with materialThe extract was dried over anhydrous magnesium sulfate
6. concentrationconcentrated
7. customThe residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=1:1)