反应详情

To solution of 2,4-dibenzyloxyphenylacetic acid (2.0 g) and para-nitrophenol (920 mg) in N,N-dimethylformamide anhydride (20 ml) is added drop by drop a solution of of dicyclohexylcarbodiimide (1.2 g) in N,N-dimethylformamide anhydride (10 ml) at 0 ° C. and the mixture is left to stand at room temperature (15 ° C.) for 22 hours. The resulting solution is concentrated under reduced pressure to dryness and thereto is added ethyl acetate (70 ml). The precipitate produced is removed by filtration. The filtrate is concentrated under reduced pressure and the residue is separated and purified by use of a silica gel column [silica gel: 350 ml ; developer : hexane-ethyl acetate mixture (4:1)] to yield para-nitrophenyl 2,4-dibenzyloxyphenylacetate (0.70 g; yield 26%).

1. waitthe mixture is left
2. customto stand at room temperature
3. custom(15 ° C.)
4. customfor 22 hours
5. concentrationThe resulting solution is concentrated under reduced pressure to dryness
6. additionis added ethyl acetate (70 ml)
7. customThe precipitate produced
8. customis removed by filtration
9. concentrationThe filtrate is concentrated under reduced pressure
10. customthe residue is separated
11. custompurified by use of a silica gel column [silica gel: 350 ml ; developer : hexane-ethyl acetate mixture (4:1)]