8results about How to "Simplify purification operations" patented technology

The invention relates to the technical field of medical intermediate processing, and discloses a preparation method of polyfluoro substituted benzene series compounds based on diazonium salt, which comprises the following steps: 1) taking fluoroaniline substances, fluoboric acid and sodium nitrite as raw materials, reacting for 2-4 hours at the reaction temperature of lower than 10 DEG C, and performing suction filtration and purification to obtain a diazonium salt intermediate; 2) distilling the diazonium salt intermediate at 130-150 DEG C, and decomposing the diazonium salt intermediate to obtain a compound which is o-difluorobenzene, p-difluorobenzene or 1, 2, 4-trifluorobenzene; according to the method, a diazonium salt intermediate is prepared by taking a fluorine-containing aniline substance, fluoboric acid and sodium nitrite as raw materials, the yield of the step can reach 95% or above, the yield of pure o-difluorobenzene obtained by heating and decomposing diazonium salt can reach 80% or above, and the yield of p-difluorobenzene can also reach 85% or above; the yield of the obtained 1, 2, 4-trifluorobenzene can also reach 84% or above; the method is short in process, mild in reaction, simple in operation, high in product yield and simple in purification operation, and the product purity can reach 99% or above.

The application discloses a green preparation method of 4,4'-difluorobenzophenone. The method uses 4,4'-difluorobenzene as raw material, potassium bromide as catalyst, acetic acid as solvent, and oxygen as oxidant, and 4,4'-difluorobenzophenone is generated in high selectivity through one-step oxidation under mild conditions. The application surprisingly finds that in the presence of potassium bromide, a new non-metallic catalytic oxidation system of potassium bromide / acetic acid / oxygen is used to realize high-efficiency and high-selectivity conversion of the C-H bond at the benzyl position. Compared with the traditional method, the application does not need to use a transition metal catalyst, does not need to use carbon tetrachloride and other materials damaging the ozone layer, and does not need to involve a dangerous intermediate such as a diazonium salt, the process route is short, the atomic economy is high, the product yield is high, the product purity is high, the catalyst is cheap and easy to obtain, and the application has excellent industrial application prospect and green chemistry characteristics.

The present invention provides a kind of synthetic method of ceftiofur sodium, belongs to the field of drug synthesis technology, including: 7-ACF and AE active ester are provided, and amidation reaction is carried out in dichloromethane solvent; A hydrolysis solvent is provided, and a hydrolysis solvent is used for hydrolysis extraction of the reaction system of amidation reaction; An extraction solvent is provided, and an extraction solvent is used for removing impurities from the aqueous phase obtained by hydrolysis extraction, and cooling centrifugation is carried out to the obtained extraction system to obtain a thiofuran intermediate; And, a salt-forming agent is provided, and after the thiofuran intermediate and the salt-forming agent carry out salt-forming reaction, after filtration and drying, a ceftiofur sodium product is obtained. The method can reduce the amount of by-product generation in the amidation reaction, and the thiofuran intermediate is subjected to the refining operation of multiple extractions and cooling centrifugation, and the quality and yield of the thiofuran intermediate are improved, so as to improve the content and purity of the ceftiofur sodium product, reduce the impurity content, and the product yield is high, and the stability is good.

The utility model relates to the technical field of leather processing, in particular to a high-temperature foaming device for leather production, which comprises a drying oven main body, a corner of the rear part of the upper end of the drying oven main body is communicated with a barrel, a fan I is arranged in front of the barrel, an air outlet end of the fan I is communicated with an L-shaped pipe, the L-shaped pipe fixedly penetrates through the inner wall of the barrel, and the barrel is provided with an air inlet. A first sealing assembly is arranged between the L-shaped pipe and the barrel, a pipe body communicates with a corner of the front portion of the upper end of the drying oven body, a second fan is arranged behind the pipe body, the second fan and the first fan are both fixedly installed at the upper end of the drying oven body, and the air outlet end of the second fan communicates with the L-shaped pipe. And a cylindrical barrel is fixedly sleeved on the outer wall of the pipe body close to the edge of the upper part. Before a worker takes out foamed leather, pungent gas in the drying oven main body can be filtered and purified, the purification operation is simple and easy, adverse effects on the body health of the worker are avoided, and environment protection is also facilitated.

The invention provides a continuous purification method of a pyroxasulfone intermediate, which comprises the following steps: a synthesized mixed solution containing 3-chloro-5, 5-dimethyl-4, 5-dihydroisoxazole of the pyroxasulfone intermediate enters a continuous extraction liquid separation device, the mixed solution is subjected to extraction separation to obtain an organic phase and a water phase, and the lower organic phase is extracted to a buffer tank; pumping the organic phase in the buffer tank into the middle section of a continuous distillation device, keeping the continuous distillation device at negative pressure, and obtaining a primary purified product at the bottom of the continuous distillation device; and pumping the primary purified product into the middle part of a continuous rectification device, and keeping the continuous rectification device at negative pressure, wherein the liquid extracted by a first-stage condenser is the pyroxasulfone intermediate. The reaction liquid is kept to be distilled, rectified and condensed at a specific temperature during post-treatment, so that the influence of high-temperature fractions (component 2) on the subsequent oxidation reaction is effectively removed, and the purity and yield of the final product pyroxasulfone are improved. And a high-purity product (the GC purity is 99% or above) is obtained, and the method has great significance in a full-continuous process.

The invention provides an enterokinase light chain recombinant protein and application and a method for efficient soluble expression of a recombinant enterokinase light chain, the enterokinase light chain recombinant protein is composed of more than two fusion proteins AgSg or mutants thereof and an enterokinase light chain or mutants thereof, the amino acid sequence of the fusion proteins AgSg is shown as SEQ ID NO.3, and the amino acid sequence of the fusion proteins AgSg is shown as SEQ ID NO.3. The amino acid sequence of the enterokinase light chain is as shown in SEQ ID NO. 1; according to the enterokinase light chain recombinant protein, a specific amount of fusion protein AgSg derived from the N end of spider silk sericin is fused with an enterokinase light chain or a mutant thereof in a series connection manner, so that the expression quantity of the enterokinase light chain or / and the mutant can be remarkably improved, and the enterokinase light chain or / and the mutant can be expressed in a soluble form; the defects that a traditional escherichia coli system is low in expression quantity and expression and purification are difficult in an inclusion body form are overcome, and the method can be applied to production of high-efficiency soluble enterokinase light chains.

The invention discloses a preparation method of diethylhexyl butyrylamide triazinone, which comprises the following steps: S1, reacting a first intermediate N-tert-butyl-4-[(4, 6-dichloro-1, 3, 5-triazine) amino] benzamide with p-aminobenzonitrile in a solvent to obtain a second intermediate 4-(4, 6-bis ((4-cyanophenyl) amino)-1, 3, 5-triazine) amino] benzamide; the preparation method comprises the following steps: adding 2-(3, 5-triazine-2-yl) amino)-N-(tert-butyl) benzamide; s2, enabling the second intermediate to react with isooctanol under the condition of acid catalysis to obtain the diethylhexyl butyrylamide triazinone. According to the preparation method, common impurities in other routes can be avoided, the product purity is high, the method is environmentally friendly, the solvent is easy to recycle and reuse, the production cost is low, and the method is suitable for large-scale industrial production.

The invention discloses a synthesis method of amidinotaurine, which comprises the following steps: by taking thiourea and sulfonate as initial raw materials, carrying out heating reaction in a water phase system to generate S-alkyl thiourea sulfonate, then adding taurine, carrying out substitution reaction to generate amidinotaurine, regulating the pH value of the system to alkalescence, cooling, crystallizing and separating to obtain the amidinotaurine. According to the synthesis method of the amidinotaurine, the amidinotaurine is synthesized by taking water as a reaction medium and taking thiourea, sulfonate and taurine as raw materials through a one-pot method, the raw material cost is low, and the economic benefit is good; according to the method, the reaction speed of the product can be increased, the separation and purification operation is simplified, the production efficiency can be improved, and the obtained amidinotaurine is high in yield and purity and has market popularization value.