反应详情

15 ml of cooled 0.1 N aqueous potassium hydroxide solution are added, whilst stirring, to a solution, cooled in an ice bath, of 382 mg of 7β-phenoxyacetamido-3-methoxy-ceph-2-em-4α-carboxylic acid methyl ester in 30 ml of tetrahydrofurane. After 5 minutes, 100 ml of water and 70 ml of methylene chloride are added and the mixture is acidified by adding 10 ml of 1 N aqueous hydrochloric acid. The methylene chloride phase is separated off and the aqueous phase is extracted with 30 ml of methylene chloride. The combined organic phases are dried over sodium sulphate and concentrated by evaporation in vacuo. The residue is crystallised from chloroform/diethyl ether and gives 7β-phenoxyacetamido-3-methoxy-ceph-2-em-4α-carboxylic acid of melting point 142° C. (decomposition).

1. customThe methylene chloride phase is separated off
2. extractionthe aqueous phase is extracted with 30 ml of methylene chloride
3. dry with materialThe combined organic phases are dried over sodium sulphate
4. concentrationconcentrated by evaporation in vacuo
5. customThe residue is crystallised from chloroform/diethyl ether