反应详情

5.23 g of 2-(2-tritylaminothiazol-4-yl)-2-((1-methylimidazol-5-yl)methoxyimino)acetic acid and 3.28 g of tertiary butyl 7β-amino-3-acetoxymethyl-3-cephem-4-carboxylate were suspended in 200 ml of methylene chloride and 1.35 g of 1-hydroxybenzotriazole was added thereto. A mixture of 2.27 g of DCC and 20 ml of methylene chloride was added to the mixture under stirring and cooling in an ice-bath. The resulting mixture was stirred for 1 hour at the same temperature and then stirred for 23 hours at room temperature. The insoluble material was removed by filtration and the filtrate was concentrated to dryness in vacuo. The residue was purified by silica gel column chromatography with a 1% methanol-chloroform eluent to give 6.49 g of tertiary butyl 7β-(2-(2-tritylaminothiazol-4-yl)-2-((1-methylimidazol-5-yl)methoxyimino)acetamido)-3-acetoxymethyl-3-cephem-4-carboxylate (syn isomer) as a powder.

1. additionwas added to the mixture
2. temperaturecooling in an ice-bath
3. stirringThe resulting mixture was stirred for 1 hour at the same temperature
4. stirringstirred for 23 hours at room temperature
5. customThe insoluble material was removed by filtration
6. concentrationthe filtrate was concentrated to dryness in vacuo
7. customThe residue was purified by silica gel column chromatography with a 1% methanol-chloroform eluent