反应详情

温度

50 °C

Formic acid (0.29 g, 6.22 mmol) and purified water (5 ml) were added to ethyl 4-(2-amino-4-ethoxycarbonylphenyl)piperazine-1-carboxylate (2.0 g, 6.22 mmol) prepared in the Step 38-1-2. A 30% hydrogen peroxide solution (0.63 g, 18.67 mmol) was further added thereto, and the mixture was heated and stirred at 50° C. Formic acid (2 ml) and 2 ml of a 30% hydrogen peroxide solution were further added to the mixture. The resulting mixture was stirred for another one hour, then allowed to cool, and stirred. After being cooled to a room temperature, 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 (n-hexane:ethyl acetate=1:1 to 1:2) to give the title compound (0.22 g, 11%) as a white powder.

1. customprepared in the Step 38-1-2
2. temperaturethe mixture was heated
3. stirringThe resulting mixture was stirred for another one hour
4. temperatureto cool
5. stirringstirred
6. temperatureAfter being cooled to a room temperature
7. extractionsubjected to extraction with ethyl acetate
8. dry with materialThe extract was dried over anhydrous magnesium sulfate
9. concentrationconcentrated
10. customThe concentrate was purified by silica gel column chromatography (n-hexane:ethyl acetate=1:1 to 1:2)