反应详情

温度

50 °C

A 5-L three-necked round-bottomed flask, equipped with a mechanical stirrer and thermocouple, was charged with the racemic acid of Example 4 (392.87 g, 0.964 mol) and dissolved in isopropanol (2.0 L) to afford a light yellow solution. While stirring vigorously the reaction mixture was heated to 50° C. and then (S)-(α-methylbenzylamine was added over five minutes, causing the reaction tp turn slightly green in color. Heating was discontinued and a seed crystal was preferably added. Crystallization was observed within 15 minutes. The reaction mixture was cooled to room temperature over 2 hours while stirring and then the crystals were collected by filtration and washed with isopropanol (500 mL). After drying under vacuum, 208 g of the title compound as a 1:1 salt with (S)-α-methylbenzylamine (41% yield corrected for about 9% of 2-propanol as determined by 1H NMR; about 99.9% by HPLC) was obtained as a fluffy white solid. The product was found to be 99.3% enantiomerically pure as determined by capillary electrophoresis.

1. customA 5-L three-necked round-bottomed flask, equipped with a mechanical stirrer
2. customto afford a light yellow solution
3. temperatureHeating
4. additiona seed crystal was preferably added
5. customCrystallization
6. temperatureThe reaction mixture was cooled to room temperature over 2 hours
7. stirringwhile stirring
8. filtrationthe crystals were collected by filtration
9. washwashed with isopropanol (500 mL)