1454 results about "Racemization" patented technology

The invention relates to the field of polypeptides, in particular to a method for preparing semaglutide. The method has the advantages that Fmoc-Lys (Alloc)-OH protection amino acid is used as a raw material, de-protection is carried out by the aid of selected Pd (PPh3) 4, accordingly, operation procedures are simple, only 1-2 times of simple elimination reaction operation are required, each elimination reaction operation is carried out for 10-30 min, side reaction is prevented, the operation procedures are safe, and enlarged production can be facilitated; Boc-His (Boc)-OH. DCHA and Boc-His (Trt)-OH are used as raw materials in the procedures, and accordingly His racemization risks can be reduced to the greatest extent; special fragments are coupled, and accordingly the synthesis efficiency can be improved.

The invention discloses a new synthesizing technique of chiral drug (S)-alpha-ethyl-2-oxo-1-pyrrolidine acetamide ( left Piracetam) intermediate (S)-(+)-2-aminobutanamide hydrochlorate, which comprises the following steps: adopting 2-brobutyrate as initial raw material; aminating; esterifying; ammonolyzing; detaching; looping; obtaining the object compound; making mixed rotary free alkaline (+-)-2-aminobutanamide; adopting half-quantum resolution method to connect chemical detaching salt to evolve salt; removing the detaching agent through alkalization; obtaining the (S)-(+)-2-aminobutanamide hydrochlorate with optical activity; using the mother liquor to make the product. The invention improves the receiving rate and saves the cost of raw material with simply technical operation and low cost, which resolves the resolved mother liquor after racemic action again to reduce the pollution of environment, therefore fitting for industrialized manufacturing.

The present invention relates to new chiral salen catalysts and methods for the preparation of chiral compounds from racemic epoxides by using new catalyst. More particularly, the present invention is to provide novel chiral salen catalysts and their uses for producing chiral compounds having high optical purity to be used as raw materials for preparing chiral medicines or food additives in a large scale economically, wherein the chirl salen catalyst having a particular molecules structure can be reused continuously without any activating process of used catalysts and cause no or little racemization after the reaction is completed because it maintains its catalytic activity after the reaction process.

The subject disclosure provides compositions for reducing serum cholesterol and/or triglyceride levels in subjects. These compositions can comprise racemic β-hydroxybutyrate or D-β-hydroxybutyrate, optionally in the acid form, physiologically compatible salts of racemic β-hydroxybutyrate or D-β-hydroxybutyrate, esters of D-β-hydroxybutyrate, oligomers of D-β-hydroxybutyrate containing from 2 to 20 or more monomeric units in either linear or cyclic form, racemic 1,3 butandiol or R-1,3 butandiol alone and can be, optionally, administered in conjunction with a low fat diet to a subject. Alternatively, compositions comprising racemic β-hydroxybutyrate or D-β-hydroxybutyrate, optionally in the acid form, physiologically compatible salts of racemic β-hydroxybutyrate or D-β-hydroxybutyrate, esters of D-β-hydroxybutyrate, oligomers of D-β-hydroxybutyrate containing from 2 to 20 or more monomeric units in either linear or cyclic form, racemic 1,3 butandiol, R-1,3 butandiol or combinations thereof can be formulated as nutritional supplements (also referred to as nutritional compositions) or incorporated into therapeutic compositions containing a) anti-hypertensive agents; b) anti-inflammatory agents; c) glucose lowering agents; or d) anti-lipemic agents) which are administered to a subject, optionally in combination with a low fat diet, in order to cause a reduction or lowering of: serum cholesterol levels; triglyceride levels; serum glucose levels, serum homocysteine levels, inflammatory proteins (e.g., C reactive protein) and/or hypertension in treated subjects. Alternatively, compositions disclosed herein can be administered alone, or in combination with other therapeutic agents to prevent or reverse vascular disease.

The invention discloses an enzyme-chemocatalysis racemization removing preparation method for L-glufosinate-ammonium. According to the method, a one-pot reaction manner is adopted, under the molecular oxygen, immobilization D-amino acid oxidase catalyzes D-enantiomer in an enantioselectivity mode into 2-imino-4-(hydroxy methyl phosphonyl) butyric acid in a dehydrogenation mode, and palladium-ammonium formate catalyzes 2-imino -4-(hydroxy methyl phosphonyl) butyric acid into DL-glufosinate-ammonium in an in-situ reduction mode. Hydrogen peroxide produced in the process is efficiently decomposed into water and oxygen through catalase. Complete reacemization removing of DL-glufosinate-ammonium and efficient preparing of L-glufosinate-ammonium are achieved through biological oxidation-chemical reduction circulation. The method has the advantages that the process is simple, cost is low, environmental friendliness is achieved, and energy is saved. High-concentration DL-glufosinate-ammonium can be converted into L-glufosinate-ammonium. The yield is 90%, the optical purity of the product is 99%, and the method is suitable for industrial production of L-glufosinate-ammonium.

The invention relates to a method used microorganism enzyme resolution DL-pantoic acid lactone to produce D-pantoic acid. It uses the D-pantoic acid lactone hydrolase strain of the fusarium, gibberella, aspergillus, penicillium, rhizopus, gliocladium, aureobasidium to ferment and culture, uses wet thallus as coarse enzyme, DL-pantoic acid lactone as substrate to produce D-pantoic acid. L- pantoic acid lactone can be reclaimed. The DL-pantoic acid lactone gained by racemization reaction can newly be used to do resolution.

The invention provides a preparation method for clopidogrel and the salts of clopidogrel, belonging to the field of medical and chemical technology. The invention solves the problems of more reaction steps, long technical route, high cost and low purity of the existing preparation method for clopidogrel. The preparation method for clopidogrel comprises the following steps: a. synchronous resolution and racemization; b. preparation of (plus) alpha-(2 - thiophene triethylamine yl) -2 - (2 - chlorophenyl) methyl acetate; c. preparation of target product clopidogrel through cyclization reaction. The clopidogrel can generate medicinal salt with acids in a solvent. The preparation method for clopidogrel and the salts of clopidogrel has simple technology, easy operation, lower costs and higher product purity.

The invention discloses a quinazoline derivative and a pharmaceutically acceptable salt thereof showed in a formula I, or their enantiomer, diastereoisomer, tautomer, racemate, solvate, metabolic precursor or prodrug. The invention also discloses a preparation method, an intermediate, a composition and an application. The quinazoline derivative has good antineoplastic activity.

The invention relates to a stable preparation for injection by taking S-oxiracetam as active ingredient. The preparation is a composition for injection, and is formed by the S-oxiracetam or salts thereof serving as active ingredient and pharmaceutically acceptable auxiliary material. To restrain the racemization of the S-oxiracetam, when the powder injection with the active ingredient is prepared, and only the pH value of the S-oxiracetam medicament solution ranges from 4.5 to 7.0, the pH value is between 5.4 to 6.6 preferably, so that the S-oxiracetam medicament solution can be produced, and the final freeze-dried product has acceptable long stability; and moreover, when injection is produced, a rotary steam sterilization method needs to be adopted, terminal rotating sterilization is performed for 15 to 45 minutes under the temperature of 121 DEG C, and the terminal rotating sterilization is performed for 15 to 20 minutes preferably, so that the S-oxiracetam injection with high purity can be obtained and has acceptable long stability.

The present invention relates to a method for producing an optically active 3-aminopiperidine or salt thereof. In the method, a racemic nipecotamide is stereoselectively hydrolyzed to obtain an optically active nipecotamide and an optically active nipecotic acid in the presence of an enzyme source derived from an organism, and then the optically active nipecotamide is derived into an optically active aminopiperidine or salt thereof by aroylation, Hofmann rearrangement, deprotection of the amino group and further deprotection; or the optically active nipecotamide is derived into an optically active aminopiperidine or salt thereof by selective protection with BOC, Hofmann rearrangement and further deprotection. It is possible by the present invention to produce an optically active 3-aminopiperidine or salt thereof useful as a pharmaceutical intermediate from an inexpensive and easily available starting material by easy method applicable to industrial manufacturing.

The invention provides compounds of formula wherein R¹, R³, R⁴, R⁵, R⁶, R¹⁴, X, W and Z are as defined in the specification and optical isomers, racemates and tautomers thereof, and pharmaceutically acceptable salts thereof; together with processes for their preparation, pharmaceutical compositions containing them and their use in therapy. The compounds are inhibitors of human neutrophil elastase.

The invention discloses a phosphine ligand and an enantiomer or a racemic body thereof and preparation methods and applications thereof. The structural formulae of the phosphine ligand and the enantiomer or the racemic body are shown in the specifications; a phosphine ligand compound has a novel framework; complete transfer of planar chirality to axial chirality in a synthesis process is realized through a desymmetrization reaction; a synthesis method is simple and economical; during preparation of a chiral ligand, common complex chiral splitting processes are avoided; and an obtained chiral ligand has the advantages of high reaction activity, high enantioselectivity and the like in a model reaction, can be applied to catalytic reactions of a plurality of metals such as palladium, rhodium, nickel, copper, iridium, ruthenium, iron, cobalt, gold, platinum and the like, and can have a very good catalytic effect.

The present invention is method for controlling the stereoisomerism of PVB resin as well as a PVB resin having a meso/racemic stereoisomer ratio of from about 2.5 to about 5.0. Manipulation of the PVB stereoisomer ratio can provide an additional method of controlling the physical properties of PVB, in addition to or in lieu of changing additives or manipulating the PVB composition.

The invention discloses a racemization control method for an under-actuated satellite. The method comprises the following steps of: (1) determining an initial self-rotating shaft position of the under-actuated satellite by the adoption of an attitude sensor, and determining a direction and an amount of racemization control according to a position of a target self-rotating shaft; (2) determining geometric relationship between an injection control moment and a racemization control direction produced by each injection control engine, and selecting the injection control engine with the largest amount of the injection control moment in the racemization control direction as a racemization control engine; and (3) in a preliminary stage of racemization, adopting an integer multiple self-rotating period fully spraying method, in a final phase of racemization, adopting a symmetrical point spraying method, using the racemization control engine to carry out racemization control, after primary racemization is finished, enabling a planet to be naturally damped for a period of time, and then carrying out the next racemization control until a self-rotating shaft of a satellite reaches a target self-rotating shaft. According to the method, the operation of a racemization control strategy is simple and convenient, and nutation produced by racemization control can be reduced at the same time.

The invention provides a preparation method and novel use of amine compounds. Specifically, the invention provides compounds shown in the formula A or their optical isomers, racemes, solvates or pharmaceutically acceptable salts and a medical use thereof. The above compounds can be used for preparation of a pharmaceutical composition or a preparation. The pharmaceutical composition or preparationis used for (a) inhibiting a transient receptor potential channel protein TRPA1 and (b) treating diseases associated with the transient receptor potential channel protein, wherein each group is defined in the specification.

The invention discloses a space non-cooperative target electromagnetic eddy current racemization capture device and a method thereof. The device includes a working spacecraft equipped with solar panels; an observation system and a robotic arm are provided on the working spacecraft; the observing system is used to estimate the direction and speed of the target rotation, and the electromagnet is provided with an electromagnet for derotation; an end effector for capturing the target after the race is provided at the end of the robot arm. Compared with the small satellite formation-based race andcatch system, the present invention has advantages in control difficulty, fault tolerance and service life.

The invention relates to a method for preparing soematoglutide. A solid-liquid phase-binding fragment condensation scheme is adopted and includes conducting solid phase synthesis to obtain side chainprotecting peptide, conducting liquid phase fragment condensation to obtain fully protected semaglutide, then conducting cleavage to obtain crude semaglutide and conducting purification salt exchangeto obtain the semaglutide. A pseudoproline strategy is adopted to reduce by-products caused by racemization. Acccording to the method, impurities are reduced, the yield is improved, the synthesis timeis reduced, the waste liquid discharge is reduced, the synthesis cost is greatly reduced, and the method is very beneficial to industrial production.

PCT No. PCT/JP97/03166 Sec. 371 Date Feb. 8, 1999 Sec. 102(e) Date Feb. 8, 1999 PCT Filed Sep. 9, 1997 PCT Pub. No. WO98/11088 PCT Pub. Date Mar. 19, 1998A process for preparing a 1,3-dioxolane-3-methanol (5) in a racemic form or an optically active form involves reacting with an alcohol in a base (i) a 3-halogeno-1,2-propanediol (1a) in which X is halogen atom, or (ii) a glycidol effecting a 3-alkoxy-1,2-propanediol, acetalizing the 3-alkoxy-1,2-propanediol in an acid, and hydrogenolyzing the resulting 4-alkoxy-1,3-dioxolane in a reduction catalyst to effect the 1,3-dioxolane-3-methanol (5) in which each of R1 and R2 is a hydrogen atom, alkyl having 1 to 4 carbon atoms or phenyl, or R1 and R2 together form a cycloalkyl ring having 3 to 6 carbon atoms.

The invention relates to a preparation method of duloxetine, which takes 2-acetyl phenol, paraformaldehyde and dimethylamine hydrochloride as raw materials to obtain the target product by five steps of Mannich reaction, reduction, resolution, etherification and demethylation, and optimizes the reaction conditions of resolution and etherification, wherein, the resolution reaction comprises the steps of one-time resolution, racemization-resolution and secondary racemization-resolution. The invention can improve the yield of the duloxetine and reduce the production cost, and is easy for industrial production.