反应详情

The above experiment in Example 2 was carried out on a 24-fold scale to prepare an aldol reaction mixture containing 4-hydroxy-4-(3-indolylmethyl)-2-hydroxyiminoglutaric acid. The resulting aldol reaction mixture was adjusted to pH 1.2 by addition of 12N hydrochloric acid and extracted twice with ethyl acetate (100 ml×2). The organic layer was washed with saturated brine, dried with anhydrous magnesium sulfate, filtered to remove the magnesium sulfate, and concentrated with an evaporator to yield the residue. 28% Ammonia water (20 ml) was added, and then 200 ml of ethanol was added, and the mixture was preserved at 5° C. for 3 days. The precipitated crystals were collected by filtration and dried under reduced pressure to yield 4-hydroxy-4-(3-indolylmethyl)-2-hydroxyiminoglutaric acid diammonium salt (2.2 g)(purity 88%; yield 23%). The selectivity for the enantiomer was 44% ee for the 4R isomer.

1. customto prepare
2. customan aldol reaction mixture
3. customThe resulting aldol reaction mixture
4. extractionextracted twice with ethyl acetate (100 ml×2)
5. washThe organic layer was washed with saturated brine
6. dry with materialdried with anhydrous magnesium sulfate
7. filtrationfiltered
8. customto remove the magnesium sulfate
9. concentrationconcentrated with an evaporator
10. customto yield the residue
11. filtrationThe precipitated crystals were collected by filtration
12. customdried under reduced pressure