30-04-2014 дата публикации
Номер: CN103755663A
Принадлежит:
The invention relates to a process for recycling L-cis-lactam as a diltiazem intermediate by-product. The process comprises the following steps of: reacting by using L-cis-lactam as a raw material, IBX as an oxidizing agent, and DMSO with the water content of 5-15% as a solvent, performing TLC detection and stopping reaction until the raw material disappears, dissolving in water, stirring for an hour and then performing filtration, collecting filter cakes, washing the filter cakes using ethyl acetate, drying a mother liquor, reducing pressure and concentrating to obtain 2-(4-methoxyphenyl)-1,5-benzothiazepin-3,4(2H,5H)-diketone, drying and recycling the filter cakes, and then obtaining IBA. According to the invention, IBX with high selectivity is used as an oxidizing agent, the reaction condition is moderate, the condition of absolute no water and oxygen is not required, the reaction time is shorter, the post-processing is simple, environmental pollution does not exist, and the reduction ...
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