反应详情

Into a 250 mL round bottomed flask equipped with an Dean-Stark distilling trap was charged 8 g (28.4 mmole) of N-benzyloxycarbonyl-L-glutamic acid, 1.45 g (50 mmole) paraformaldehyde, 28.5 mg p-toluenesulfonic acid monohydrate and 150 mL benzene. The mixture was refluxed for 8 hr during which the solution turned yellowish in color and solid appeared in the condenser and trap. Evaluation with TLC (silica gel GF, solvent: 5% methanol/dichloromethane or ethyl acetate:dichloromethane:acetic acid=1:1:0.05) indicated the reaction was complete. The reaction mixture was cooled down to room temperature, and then rotary evaporated to dryness. The residue was taken into ethyl acetate and washed with benzene. The ethyl acetate solution was dried over magnesium sulfate, filtered, and concentrated to yield the oxazolidine propionic acid product (quantitative recovery)

1. customInto a 250 mL round bottomed flask equipped with an Dean-Stark
2. distillationdistilling trap
3. temperatureThe mixture was refluxed for 8 hr during which the solution
4. customrotary evaporated to dryness
5. washwashed with benzene
6. dry with materialThe ethyl acetate solution was dried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated