反应详情

温度

25 °C

The white solid was collected by filtration to give 58.3 g (75.4%) of (L)-(−)-DTTA which compared to an authentic sample. 77.3 g of Di-p-toluoyl-D-tartaric acid ((D)-(+)-DTTA) was taken up in 550 ml of ethanol at 70° C. in a jacketed vessel. To this solution was added the Tramadol free base in 200 ml of ethanol. A precipitate formed almost immediately. The vessel was gradually cooled to 25° C. over several hours to give a fine white solid. Stirring at 25° C. was maintained overnight. The resulting copious white solid was collected at the pump, washing with 500 ml of ethanol. This gave 111.6 g of (+)-Tramadol. Di-p-toluoyl-D-tartaric acid in 85.2% yield, with a de of 97.3%. Reslurrying of this salt from 500 ml of ethanol as above gave 108.5 g of the (+)-Tramadol-containing salt, with a de of >99% in 97.8% yield. [α]D 589=+103.30° (C=1.15, MeOH). MP=162.1-167.8° C. (DSC).

1. customA precipitate formed almost immediately
2. customto give a fine white solid
3. temperaturewas maintained overnight
4. customThe resulting copious white solid was collected at the pump
5. washwashing with 500 ml of ethanol