35results about How to "Low color level" patented technology

The invention relates to a method for preparing an antibacterial compound, in particular to a method for preparing a ceftezole sodium compound. The method comprises the following steps of: 1, synthesizing TZT II, and reacting 2-mercapto-1,3,4 thiadiazole and 7-aminocephalosporanic acid (ACA) to obtain TZT, wherein dimethyl carbonate is used as a reaction solvent; a boron trifluoride-dimethyl carbonate complex is used as a catalyst; after reaction, the agent used by adjusting pH of reaction liquid is sodium carbonate; the weight ratio of boron trifluoride to 7-ACA is 0.7 to 1.3; and 2, synthesizing anhydride I, namely reacting 1H-tetrazole-1-acetic acid and pivaloyl chloride to obtain anhydride; 3, synthesizing ceftezole III, namely reacting TZT II and anhydride I to obtain ceftezole; and 4, synthesizing ceftezole sodium IV, namely reacting ceftezole and sodium salt to obtain ceftezole sodium IV, wherein salt is sodium hydroxide.

The invention discloses a method for preparing cefmenoxime hydrochloride, which comprises the following steps: uniformly mixing 7-ACT hydrochloride shown in a formula II and AE active ester shown in a formula III under the condition that methylene dichloride and a solvent exist for condensation reaction and obtaining the cefmenoxime hydrochloride shown in a formula I after reaction. The method has the benefits that the cefmenoxime hydrochloride can be synthesized in one step, the cefmenoxime hydrochloride is not required to be separated, a reversely-dropping crystallization method is adopted, the synthetic line is short, the cost is low, the reaction conditions are wild, and the production is convenient; and the cefmenoxime hydrochloride product is high in yield and purity and low in color grade and has an important application value.

The invention discloses a purification method of cefepime dihydrochloride, and belongs to the field of chemical pharmacy. The method comprises the following steps: cefepime dihydrochloride arginine istaken as a raw material, a complexing agent is added in the dissolving solution of the cefepime dihydrochloride arginine for decoloration; and a dispersant and a crystallization agent are added intothe decolorated solution for crystallization, so as to finally obtain the cefepime dihydrochloride. The purification method can enable the cefepime dihydrochloride arginine which does not meet the quality standard to be fully recycled, therefore the prepared cefepime dihydrochloride has the advantages of high content, less impurities and high stability; and the preparation method is simple, energy-saving and environmental-friendly, thereby being suitable for large-scale industrial production.

The invention discloses a preparation method of sulbactam acid, and belongs to the field of preparation of pharmaceutical intermediates. The preparation method comprises the steps of: adopting sodiumsulbacetanate as a raw material, adding a dissolution-assistant agent to a concentrated liquid, introducing carbon dioxide at the same time, and performing crystallization so as to obtain sulbatam. Through the method, sodium sulbacetanate which does not meet the quality standard can be recycled and utilized fully, and the prepared sulbactam acid has the advantages of high content, less impurities,low color grade, good fluidity and good stability; and the preparation method is simple, energy-saving and environmentally friendly, and is suitable for large-scale industrial production.

The invention discloses a method for synthesizing ceftizoxime acid by a one-pot method. The method comprises the following steps: reacting 7-ANCA and AE-active ester in a solvent system of water and tetrahydrofuran in the presence of organic alkali, regulating the pH value of the reaction system to 2-3 after the reaction is finished, and carrying out crystal growing, filtering, washing and dryingto obtain the ceftizoxime acid. According to the method, the ceftizoxime acid is synthesized by adopting the one-pot method, the process conditions are mild, an extracting agent does not need to be added for extraction separation, an adsorbent does not need to be added, acid is directly used for neutralization and crystallization after reaction, operation is convenient, and the solvent can be recycled.

The invention discloses a method for purifying cefeprime hydrochloride and belongs to the field of chemical pharmaceutical. The method includes: taking a coarse product of the cefeprime hydrochlorideas a raw material; adjusting the pH value of solving liquid of the coarse product of the cefeprime hydrochloride and adding a dispersing agent to obtain the cefeprime hydrochloride after crystallization of isoelectric points. The purity of the cefeprime hydrochloride can be improved, and the prepared cefeprime hydrochloride has the advantages of low color level, uniform particle size and good fluidity.

The invention provides a cefoxitin anhydrous crystal. Peaks exist at 2theta angles of 12.0 degrees, 15.7 degrees, 18.8 degrees and 22.6 degrees of the X-ray diffraction pattern of the crystal. In a differential thermal analysis diagram, an endothermic peak exists at 170.0 degrees and exothermic peak exists at 172.7 degrees. The invention additionally provides a method for preparing the cefoxitin anhydrous crystal and a method for preparing cefoxitin sodium by using the cefoxitin anhydrous crystal. The impurity content of the cefoxitin anhydrous crystal is low, the color level of the cefoxitinsodium is reduced and the application prospect of cefoxitin acid drugs is improved.