反应详情

温度

2.5 °C

To a cold (0-5° C.) suspension of Levodopa (197.2 g, 1.0 mol) in water (1.18 L) was added 32% aqueous HCl (159.5 g, 1.4 mol). The resulting solution was cooled to 0-5° C., and 37% formaldehyde water solution (243.24 g, 3.0 mol) was added. The resulting solution was allowed to warm to 20-25° C., and stirred at 20-25° C. for 10 h. The reaction solution was cooled to 0-5° C., and 2 N aqueous NaOH (700 mL, 1.4 mol) was slowly added to adjust pH to 5-5.5. White or light yellow solids precipitated during the addition. The resulting suspension was stirred at 0-5° C. for 2-3 h. The mixture was filtered, and rinsed with water (2×500 mL). The solids were dried under vacuum to give 199.52 g of a light yellow solid. Yield=95.3%.

1. temperatureto warm to 20-25° C.
2. temperatureThe reaction solution was cooled to 0-5° C.
3. customWhite or light yellow solids precipitated during the addition
4. stirringThe resulting suspension was stirred at 0-5° C. for 2-3 h
5. filtrationThe mixture was filtered
6. washrinsed with water (2×500 mL)
7. customThe solids were dried under vacuum