تفاعل #214836

معادلة التفاعل

3-benzylthio-7β-phenoxyacetylamino-3-cephem-4-carboxylic acid p-nitrobenzyl ester

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3-benzylthio-7β-phenoxyacetylamino-3-cephem-4-carboxylic acid

المذيبات

acetic acid

ظروف التفاعل

المعالجة

1. 1
   أخرىThe solvent is removed in vacuo
2. 2
   workup.STIRRINGthe residue is stirred with ethyl acetate
3. 3
   ترشيحfiltered
4. 4
   استخلاصThe solution is extracted with aqueous sodium bicarbonate solution and water
5. 5
   غسيلThe combined aqueous phases are washed with ethyl acetate
6. 6
   استخلاصextracted with ethyl acetate
7. 7
   تجفيفThe organic phase is dried over sodium sulphate
8. 8
   ترشيحfiltered
9. 9
   أخرىevaporated in vacuo
10. 10
    أخرىThe residue is chromatographed on silica gel with toluene containing 10% of acetone

الإجراء التجريبي

425 mg of activated zinc powder are added to a solution of 425 mg (0.72 mmol) of 3-benzylthio-7β-phenoxyacetylamino-3-cephem-4-carboxylic acid p-nitrobenzyl ester in 40 ml of glacial acetic acid and the mixture is stirred vigorously for 2 hours at room temperature and under nitrogen. The solvent is removed in vacuo and the residue is stirred with ethyl acetate and filtered. The solution is extracted with aqueous sodium bicarbonate solution and water. The combined aqueous phases are washed with ethyl acetate, acidified with hydrochloric acid and extracted with ethyl acetate. The organic phase is dried over sodium sulphate, filtered and evaporated in vacuo. The residue is chromatographed on silica gel with toluene containing 10% of acetone and gives 3-benzylthio-7β-phenoxyacetylamino-3-cephem-4-carboxylic acid; [α]D20° =+19±1° (c=0.8; chloroform); IR spectrum (methylene chloride): characteristic bands at 5.61 and 5.90μ.

المصدر