Reaktion #1006107
ord-0d0ebac5ca93449d909b1969f5d7fd42
Reaktionsgleichung
Reagenzien
Reaktionsbedingungen
Aufarbeitung
- 1SonstigeA 3 L 3-necked round bottom flask was equipped with a mechanical stirrer
- 2TemperaturThe stirred slurry was heated
- 3Temperaturto reflux for 1 hour
- 4FiltrationThe slurry was filtered
- 5Waschenwashed with methanol (250 L)
- 6SonstigeThe solid was air-dried
- 7Sonstigedried in vacuo at ambient temperature to a constant weight
- 8Sonstigegiving 109.5 g (98% yield) of the crude product (85.8% ee)
- 9Temperaturto reflux for 1 hour
- 10Temperaturcooled to room temperature
- 11workup.STIRRINGstirred for an additional 3 hours at ambient temperature
- 12FiltrationThe slurry was filtered
- 13Waschenthe filter cake was washed with methanol (200 mL)
- 14SonstigeThe solid was air-dried
- 15Sonstigedried in vacuo at 30° C. to a constant weight
Vorschrift
A 3 L 3-necked round bottom flask was equipped with a mechanical stirrer, thermometer, and condenser and charged with 2-(3-ethoxy-4-methoxyphenyl)-1-(methylsulphonyl)-eth-2-ylamine (137.0 g, 500 mmol), N-acetyl-L-leucine (52 g, 300 mmol), and methanol (1.0 L). The stirred slurry was heated to reflux for 1 hour. The stirred mixture was allowed to cool to ambient temperature and stirring was continued for another 3 hours at ambient temperature. The slurry was filtered and washed with methanol (250 L). The solid was air-dried and then dried in vacuo at ambient temperature to a constant weight, giving 109.5 g (98% yield) of the crude product (85.8% ee). The crude solid (55.0 g) and methanol (440 mL) were brought to reflux for 1 hour, cooled to room temperature and stirred for an additional 3 hours at ambient temperature. The slurry was filtered and the filter cake was washed with methanol (200 mL). The solid was air-dried and then dried in vacuo at 30° C. to a constant weight, yielding 49.6 g (90% recovery) of (S)-2-(3-ethoxy-4-methoxyphenyl)-1-(methylsulphonyl)-eth-2-ylamine-N-acetyl-L-leucine salt (98.4% ee). Chiral HPLC (1/99 EtOH/20 mM KH2PO4@pH 7.0, Ultron Chiral ES-OVS from Agilent Technologies, 150 mm×4.6 mm, 0.5 mL/min., @240 nm): 18.4 min (S-isomer, 99.2%), 25.5 min (R-isomer, 0.8%).