反应详情

A mixture of ethyl 3-[1-(4-hydroxybenzyl)-4-phenyl-3-pyrrolyl]propionate (1.30 g), 4-chloromethyl-5-methyl-2-(2-thienyl)oxazole (0.95 g), potassium carbonate (1.20 g) and N,N-dimethylformamide (15 ml) was stirred at room temperature overnight. The reaction mixture was poured into dilute hydrochloric acid, which was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated aqueous sodium chloride solution, dried (MgSO4), and then concentrated. The residue was subjected to silica gel column chromatography, and an oily substance was obtained from the fraction eluted with ethyl acetate-hexane (1:2, volume ratio). A mixture of the oily substance obtained, 1N aqueous sodium hydroxide solution (8 ml), tetrahydrofuran (10 ml) and ethanol (8 ml) was stirred at room temperature for 3 hours and the organic solvent was removed under reduced pressure. After adding water, the residue was acidified by adding 1N hydrochloric acid. The colorless crystals obtained were collected by filtration to yield 3-[1-[4-[5-methyl-2-(2-thienyl)-4-oxazolylmethoxy]benzyl]-4-phenyl-3-pyrrolyl]propionic acid (1.43 g, yield: 77%). This was recrystallized from ethyl acetate-hexane. Melting point: 117–118° C.

1. extractionwas extracted with ethyl acetate
2. washThe ethyl acetate layer was washed with saturated aqueous sodium chloride solution
3. dry with materialdried (MgSO4)
4. concentrationconcentrated
5. customan oily substance was obtained from the fraction
6. washeluted with ethyl acetate-hexane (1:2, volume ratio)
7. additionA mixture of the oily substance
8. customobtained
9. customthe organic solvent was removed under reduced pressure
10. additionAfter adding water
11. additionby adding 1N hydrochloric acid
12. customThe colorless crystals obtained
13. filtrationwere collected by filtration