46results about How to "Strong reaction selectivity" patented technology

The invention discloses a florfenicol midbody, a preparation method thereof and a preparation method of florfenicol, and belongs to the field of veterinary drug preparation. The invention provides the florfenicol midbody shown in a formula IV, wherein R1 is dimethyl sulfide or methylene sulphonyl or methyl sulphonyl, R2 is TBS- or TMS- or MOM- or THP-, R3 is shown in the description, and R4 is dichloroacetyl or benzoyl or t-butyloxycarboryl. The invention further provides a preparation of the florfenicol midbody shown in the formula IV and a preparation method of florfenicol. The obtained florfenicol is low in cost, simple in technology and high in yield, and the product chirality purity reaches up to 98%.

The invention discloses graphene oxide modified by a betaine type zwitterionic compound and a preparation method thereof. The preparation method is as follows: firstly, the surface of graphene oxide is subjected to mercapto-treatment by hydrolysis of a mercapto-containing silane coupling agent; then, ethylene-based carboxylic acid or sulfonate betaine-type The zwitterionic compound is grafted onto the surface of the graphene oxide to obtain the graphene oxide modified by the betaine type zwitterionic compound. The betaine-type zwitterionic compound-modified graphene oxide prepared by the present invention not only has excellent biocompatibility, but also has a simple and easy preparation method, high reaction efficiency and selectivity, easy regulation, and simple post-treatment of the product. convenient. This approach provides a new avenue to improve the biocompatibility of graphene oxide. The graphene oxide modified by the betaine-type zwitterionic compound will have broad application prospects in the fields of biomedical materials such as medical devices, tissue engineering scaffolds, drug sustained release, and anti-bacterial adhesion.

The invention discloses a hydrogenation method for enhancing cetane number of inferior diesel. The method comprises the following steps: (1) sufficiently mixing the inferior diesel raw material and a powdery hydrofining catalyst in a mixer to obtain a catalyst-raw oil feed mixture; (2) adding the feed mixture and hydrogen into an ebullated bed reactor from the reactor bottom filled with a mixture of a hydrodefreezing catalyst and a hydrogenation modification catalyst, and carrying out hydrogenation reaction; (3) discharging the reaction stream containing the powdery hydrofining catalyst out of the top of the ebullated bed reactor into a stable reactor, and carrying out supplementary hydrofining; and (4) carrying out solid-liquid separation on the material obtained in the step (3), and sending the liquid phase into a fractionating system to obtain the high-quality low-pour-point low-sulfur high-cetane-number diesel product. The method reasonably combines the temperature drop in the hydrodefreezing process and the temperature rise in the hydrogenation modification process, thereby lowering the low-pour-point high-cetane-number diesel, lowering the hot-spot temperature of the device and prolonging the operating cycle on the premise of ensuring the high diesel yield.

The invention discloses a radio frequency plasma-catalyst synergic effect reaction device, which comprises components such as a non-balance plasma reaction chamber, a hollow tubular metal spiral coil with a cooling passage, a catalysis body with a catalyst, an air inlet sealing end part and air inlet end sealing flange, an exhaust sealing end part and exhaust end sealing flange, an electromagnetic shielding cover and the like. The radio frequency plasma-catalyst synergic effect reaction device belongs to a reaction device arranged by aiming at the inductance coupling radio-frequency plasma and catalyst synergic effect; the non-balance plasma reaction chamber made of quartz is used as a gas reaction passage; the metal spiral coil is used, so that corresponding other plasma generating imbalance can complete a chemical reaction through the synergic effect driving with the catalyst in the passage, so that the subsequent ingredient analysis of gas after a reaction is convenient; further, the application in aspects of the chemical engineering synthesis, greenhouse effect gas recovery utilization and renewable energy sources effective storage is realized; the advantages of high reaction selectivity, high energy utilization efficiency and the like are realized.

The invention belongs to the field of western medicine synthesis, and specifically discloses a preparation method of nefiracetam, a medicine for treating Alzheimer's disease. The preparation method activates the carboxyl group in 2-oxopyrrolidine acetic acid by N'N-dicarbonylimidazole (CDI), increases the reactivity, improves the reaction rate, reduces the occurrence of side reactions, and obtains a high product yield. The purity is high, the production cost is reduced, and it is beneficial to industrialized production.

The invention belongs to the technical field of chemical industry, and specifically relates to a method for synthesizing imidazoline derivatives with high efficiency and high atom economy. The present invention is under rare earth catalytic system, will C‑ Aryl ‑N‑ Allylamidines undergo intramolecular cyclization to imidazolines. The raw materials used in the method of the invention have wide sources or are easy to prepare, are easy to operate, can synthesize imidazoline derivatives with high yield under mild conditions, and have high reaction selectivity.

The invention discloses a carbonyl starch oxidized by a Fenton similar system, and a preparation method of the carbonyl starch. The Fenton similar system is composed of a cerous nitrate salt-a catalyst-H2O2; the catalyst is ferrous sulfate or cuprous sulfateb; starch is oxidized in aqueous phase at a temperature of 20 to 60 DEG C. The preparation method comprises following steps: (1) 30 to 50 weight portions of starch and 60 to 170 weight portions of water are mixed so as to obtain a turbid liquid, and the turbid liquid is subjected to gelatinization in water bath for 0.5 to 2h at a temperature of 50 to 70 DEG C; (2) 0.3 to 2.0 weight portions of ceric ammonium nitrate and 0.0015 to 0.0075 weight portion of the catalyst are added and mixed fully, pH value of the reaction solution is adjusted to 2.5 to 4.0, and the reaction solution is reacted for 10 to 24h at a temperature of 20 to 45 DEG C in enclosed conditions; (3) 1.5 to 10 weight portions of H2O2 is added, the temperature is adjusted to 45 to 60 DEG C, and the mixture is reacted for 3 to 7h; and (4) after that, the mixture is subjected to suction filtration, is washed for 3 times with acetone, and is dried in a vacuum oven for 12 to 24h at a temperature of 40 to 60 DEG C so as to obtain the carbonyl starch containing 10 to 20% of carbonyl and 2 to 6% of carboxyl. According to the preparation method, both carbonyl and carboxyl are introduced into starch at the same time, so that functional groups of starch molecules are increased, and application area of oxidized starch is widened.