反应详情

1.42 g of ethyl (Z)-2-[2-(2,2,2-trichloroethoxycarbonylamino)thiazol-4-yl]-2-[(2-pyrrolidon-3-yl)oxyimino]acetate are suspended in 30 ml of methanol, and 3 ml of 2N sodium hydroxide are added thereto with ice-cooling. The mixture is stirred at room temperature for one hour and then refluxed for 30 minutes with heating. Then, the mixture is concentrated under reduced pressure to dryness. 5 ml of water are added to the residue, and the aqueous mixture is washed with ethyl acetate. The aqueous mixture is adjusted to pH 2 to 3 with diluted hydrochloric acid, and the mixture is extracted with a mixture of ethyl acetate and tetrahydrofuran (2:1). The extract is dried and concentrated under reduced pressure to dryness. The residue is purified by silica gel chromatography (solvent, ethyl acetate:methanol=4:1). 0.4 g of (Z)-2-[(2-(2,2,2-trichloroethoxycarbonyl-amino)thiazol-4-yl]-2-[(2-pyrrolidon-3-yl)oxyimino]acetic acid is obtained. This product begins to gradually decompose at 190° C.

1. temperaturewith ice-cooling
2. temperaturerefluxed for 30 minutes
3. temperaturewith heating
4. concentrationThen, the mixture is concentrated under reduced pressure to dryness
5. addition5 ml of water are added to the residue
6. washthe aqueous mixture is washed with ethyl acetate
7. extractionthe mixture is extracted with a mixture of ethyl acetate and tetrahydrofuran (2:1)
8. customThe extract is dried
9. concentrationconcentrated under reduced pressure to dryness
10. customThe residue is purified by silica gel chromatography (solvent, ethyl acetate:methanol=4:1)