反应详情

To a 3 neck 3 L round bottom flask fitted with a reflux condenser, dean stark trap, thermocouple, and mechanical overhead stirrer was added 2-hydroxy-4-(methylthio)butanoic acid (130 g, 870 mmol, obtained by stirring Alimet over activated charcoal, filtering and concentrating in a rotovap), 1-octadecanol (351.2 g, 1.30 mol), sodium hydrogen sulfate (2.10 g, 17 mmol), and toluene (1000 mL). The reaction was heated to reflux with removal of water (21.5 mL) during the course of about 4 hours. The reaction was cooled to room temperature overnight and the mixture was filtered. The filtrate was washed with saturated NaHCO3 (1×500 mL), DI water (1×500 mL) and brine (1×500 mL), dried over sodium sulfate, filtered and evaporated to give light brown semi-solid (319.4 g). The semi-solid was treated with hexanes (750 mL) and the resulting mixture was filtered. The solid was washed with hexanes (250 mL) and the combined filtrate was evaporated to give an oil which solidified upon standing (278.8 g). The solid was purified by kugelrohr at 175° C. and 0.1 mm Hg vacuum to give a waxy solid remaining in the distillation pot (214.0 g, 61%). m/z 425 (MNa+).

1. customTo a 3 neck 3 L round bottom flask fitted with a reflux condenser, dean stark trap
2. customobtained
3. filtrationfiltering
4. temperatureThe reaction was heated
5. filtrationthe mixture was filtered
6. washThe filtrate was washed with saturated NaHCO3 (1×500 mL), DI water (1×500 mL) and brine (1×500 mL)
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. customevaporated