反应详情

温度

5 °C

In a 1-l. flask, flushed with nitrogen and provided with a stirrer, thermometer, two dropping funnels, and a nitrogen inlet tube was placed a solution of 46.4 g. (0.2 moles) of rac. 4-hydroxy-alpha-methylphenethylamine hydrobromide in 100 ml. of water. The flask was cooled in an ice bath, and when the temperature reached 5° C., 40 ml. of acetic anhydride (0.395 moles) and 440 ml. of 2N NaOH were added simultaneously from the two dropping funnels at approximately equivalent rates, maintaining the temperature below 5° C. An oil gradually separated during the addition, and the mixture was stirred for another 4 hours at 5° C., then allowed to come to room temperature overnight. The oil that had solidified to a mass of crystals was recovered by filtration. After washing with water the solid was dried in vacuo over KOH and CaCl2. Yield, 32 g. of mp. 92°-93.5°. An analytical sample was obtained by recrystallization from ethyl acetate-- 30°-60° C. petroleum ether; mp. 97.5° - 99° C.

1. customflask, flushed with nitrogen
2. customprovided with a stirrer
3. temperatureThe flask was cooled in an ice bath
4. customreached 5° C.
5. temperaturemaintaining the temperature below 5° C
6. customAn oil gradually separated during the addition
7. waitto come to room temperature overnight
8. filtrationwas recovered by filtration
9. washAfter washing with water the solid
10. dry with materialwas dried in vacuo over KOH and CaCl2
11. customYield