8 results about "Para-nitrobenzaldehyde" patented technology

The present invention proposes a method and use for stabilizing a simple agglomerate for pH and salt and with adjustable size. In phosphoric acid buffer solutions with different salt concentrations and pH values, the polyacrylic acid hydroxypropyl group condensation body has specific stability; hydrophobic thermal response blocks are introduced into a hydroxypropyl acrylate monomer through reversible addition-fragmentation chain transfer polymerization to regulate and control the size of a condensation body, and a phase separation behavior is shown at different temperatures; a hydrophobic block without thermal response is introduced to regulate and control the size of the aggregate, and no thermal response behavior is shown. Continuous regulation and control of the size of the aggregate from the micron level to the nano level are achieved, and the requirements of different application scenes are met. The hydroxypropyl polyacrylate condensation body can be used for packaging various dyes and drugs; high-efficiency enzyme protection is achieved, formed aggregates can protect glucose oxidase, and the retention rate of enzyme activity reaches 85% or above after treatment is conducted for 3 hours at 60 DEG C; as a micro-reactor for the reaction of generating p-nitrobenzaldehyde phenylhydrazone from p-nitrobenzaldehyde and phenylhydrazine, the reaction rate is greatly improved.

This invention discloses a Pd nanodendritic structure, its preparation method, and its application. The preparation method includes cutting a glass slide into cubes and washing it; dissolving 1-butylpyridine chloride in chloroform solution, then adding 1-naphthol, and dissolving to prepare a chloroform mixture as the oil phase in the reaction system; preparing a precursor solution as the aqueous phase in the reaction system; placing the glass slide in a cylindrical vial for later use; adding the chloroform mixture to the vial, then adding the precursor solution to form an oil-water two-phase reaction system, and allowing the reaction to stand; extracting the organic phase, transferring the product onto the glass slide, then extracting the aqueous solution, loading the obtained product onto the glass slide, washing and drying it to prepare a Pd nanodendritic structure loaded on a glass slide. The catalyst prepared by this invention through a simple and efficient oil-water interface synthesis method exhibits excellent catalytic activity and selectivity in the selective hydrogenation of p-nitrobenzaldehyde to p-aminobenzaldehyde.

The application relates to a method for preparing Pd nanospheres with rough surfaces without surfactants and application of the Pd nanospheres, wherein an ethanol aqueous solution or a methanol aqueous solution is configured, a certain amount of Pd precursors is added into the ethanol aqueous solution or the methanol aqueous solution, a reaction container is gently shaken to uniformly mix the reaction system, the reaction system is allowed to stand and react in dark conditions, the reaction product is centrifugally separated after the reaction is completed, the obtained precipitate is centrifugally washed with ultrapure water, and drying is carried out under the condition of 20-60 DEG C, so that Pd nanospheres with rough surfaces are obtained. The application does not need to use surfactants, hard templates, does not need to additionally add a reducing agent, does not need high temperature and high pressure, does not need stirring and does not need light conditions, the reaction condition is mild, and the reaction step is simple. The prepared Pd nanospheres have rough surface structures and rich pore structures, are high in purity, and have high catalytic activity and conversion rate in selective hydrogenation reaction of 4-nitrobenzaldehyde.

The invention belongs to the technical field of medical materials, and relates to an antibacterial suture line for surgical suture and a preparation method thereof. The preparation method comprises the following steps: dissolving 2-amino-5-acetylpyridine in a hydrobromic acid glacial acetic acid solution, adding a bromine-containing acetic acid solution, and reacting to obtain an intermediate 1; adding the intermediate 1 into tetrahydrofuran, adding triethylamine and acetic anhydride, and reacting to obtain an intermediate 2; adding the intermediate 2 and thiourea into absolute ethyl alcohol to react to obtain an intermediate 3; adding the intermediate 3 and p-nitrobenzaldehyde into absolute methanol, and adding glacial acetic acid to react to obtain an intermediate 4; adding phosphorus oxychloride into N, N-dimethylformamide, and adding the intermediate 4 to react to obtain an intermediate 5; dissolving the intermediate 5 in a mixed solvent, and adding cystamine to react to obtain an antibacterial agent; the medical silk suture line is soaked in dimethyl sulfoxide dissolved with the antibacterial agent, and the medical silk suture line is obtained through ultrasonic treatment, soaking, rinsing and drying. The antibacterial suture line disclosed by the invention has multi-mechanism synergistic enhanced antibacterial performance, an environment response type active release mechanism and excellent interface affinity.

The application belongs to the technical field of medical materials and relates to a bacteriostatic suture for surgical suturing and a preparation method thereof. The preparation method comprises the following steps: 2-amino-5-acetylpyridine is dissolved in a hydrobromic acid glacial acetic acid solution, an acetic acid solution containing bromine is added, and an intermediate 1 is obtained through reaction; the intermediate 1 is added to tetrahydrofuran, triethylamine and acetic anhydride are added, and an intermediate 2 is obtained through reaction; the intermediate 2 and thiourea are added to anhydrous ethanol, and an intermediate 3 is obtained through reaction; the intermediate 3 and p-nitrobenzaldehyde are added to anhydrous methanol, and an intermediate 4 is obtained through reaction; phosphorus oxychloride is added to N,N-dimethylformamide, and the intermediate 4 is added to obtain an intermediate 5 through reaction; the intermediate 5 is dissolved in a mixed solvent, and cystamine is added to obtain an antibacterial agent; and the medical silk suture is immersed in dimethyl sulfoxide containing the antibacterial agent, and is subjected to ultrasonic treatment, soaking, rinsing and drying to obtain the bacteriostatic suture. The bacteriostatic suture has the advantages of multi-mechanism synergistic enhanced bacteriostatic performance, an environment-responsive active release mechanism and excellent interface affinity.

The invention discloses transaldolase and application thereof in preparation of a chloramphenicol intermediate. Compared with the amino acid sequence shown in SEQ ID NO: 1, the transaldolase contains amino acid residue difference at C57 and / or F59 sites, wherein the 57 and 59 positions refer to the amino acid residue number in SEQ ID NO: 1. The transaldolase disclosed by the invention is utilized to catalyze and generate a target product (2S, 3R)-p-nitrobenzene serine by taking p-nitrobenzaldehyde and L-threonine as substrates, the substrate conversion rate is relatively high, and the target product has relatively high stereoselectivity.

This invention relates to a chiral preparation method for chloramphenicol. Specifically, the method uses p-nitrobenzaldehyde and glycine ester as starting materials, and an asymmetric aldol reaction occurs under the action of a pyridinium salt carbonyl catalyst. Following reduction and amidation reactions, chloramphenicol is obtained. Compared with existing technologies, this invention utilizes the strong catalytic ability of small-molecule pyridinium salt carbonyl catalysts, starting from inexpensive and readily available raw materials, to efficiently control the stereoselectivity of the aldol reaction, and to obtain the desired stereoconfiguration product, chloramphenicol, in a single dose. The preparation method of this invention reduces the protection of active groups, shortens the chiral synthetic route of chloramphenicol, is simple to operate, and is environmentally friendly.

The invention discloses a method for synthesizing a catalyst from iron mud in an icotinib synthesis process and application of the catalyst, and belongs to the field of organic synthesis. The invention provides a method for synthesizing a catalyst from iron mud in an icotinib synthesis process and application of the catalyst, the method comprises the following steps: by taking iron mud generated by reducing nitryl into amido by iron powder in the icotinib synthesis process as a raw material, firstly, adding a prepared iron mud reaction solution into a reaction container, heating the iron mud reaction solution to react for a certain period of time; and cooling, centrifuging, washing, drying in vacuum and collecting to obtain the catalyst. The method comprises the following steps: catalyzing p-nitrobenzaldehyde and 4-tert-butylphenol to react by using a catalyst to generate [5-(1, 1-dimethyl ethyl)-2-hydroxyphenyl] (4-nitrophenyl) ketone, taking p-nitrobenzaldehyde and 4-tert-butylphenol as raw materials, using an organic solvent, adding alkali, adding the catalyst, reacting under a heating condition, and carrying out suction filtration, extraction, washing, drying and rotary evaporation to obtain the [5-(1, 1-dimethyl ethyl)-2-hydroxyphenyl] (4-nitrophenyl) ketone. The method has the advantages that 1, 1-dimethyl ethyl)-2-hydroxyphenyl] (4-nitrophenyl) ketone is prepared, and the conversion rate is 65.6%;