반응 #1501302

반응 방정식

p-toluene sulfonic acid

p-nitrobenzyl 7-phenoxyacetamido-3-methylenecepham-4-carboxylate

methylene chloride

phosphorus pentachloride

→

p-nitrobenzyl 7-amino-3-methylene-cepham-4-carboxylate p-toluenesulfonate

용매

pyridine

methanol

반응 조건

후처리

1. 1
   workup.WAITFollowing a stirring period of one-hour at room temperature
2. 2
   기타the reaction mixture was evaporated in vacuo
3. 3
   기타to remove the solvents
4. 4
   workup.DISSOLUTIONthe residual reaction product mixture was dissolved in a mixture of ethyl acetate and water
5. 5
   기타the ethyl acetate layer was separated
6. 6
   세척was washed with water
7. 7
   기타dried
8. 8
   온도on cooling 600 mg

실험 절차

To a solution of 965 mg. of p-nitrobenzyl 7-phenoxyacetamido-3-methylenecepham-4-carboxylate in 10 ml. of methylene chloride were added 175 mg. of dry pyridine and 460 mg. of phosphorus pentachloride and the mixture was stirred for five hours at room temperature. Thereafter the reaction mixture was cooled to 0° C. and 50 ml. of cold methanol were added. Following a stirring period of one-hour at room temperature the reaction mixture was evaporated in vacuo to remove the solvents and the residual reaction product mixture was dissolved in a mixture of ethyl acetate and water. The pH was adjusted to pH 7 and the ethyl acetate layer was separated and was washed with water and dried. One equivalent of p-toluene sulfonic acid was added to the dried solution and on cooling 600 mg. of p-nitrobenzyl 7-amino-3-methylene-cepham-4-carboxylate p-toluenesulfonate formed as a crystalline precipitate. The product was purified by recrystallization from a mixture of 12 ml. of methanol 24 ml. of ether and 15 ml. of petroleum ether.

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