227results about How to "High chiral purity" patented technology

The invention relates to a preparing method of a phosphodiesterase 5 inhibitor tadalafil. D-methyl tryptophanate hydrochloride is adopted as an initial raw material, and is subjected to cyclization with heliotropin, N-acylation, aminolysis-cyclization, and other reactions to obtain a tadalafil crude product. The tadalafil crude product is recrystallized to obtain a tadalafil finished product. The method has characteristics of mild reaction conditions, short reaction time, high yield, good product stability and convenience for industrial production.

The invention discloses a method for preparing brivaracetam. The method for preparing brivaracetam comprises the following step that in an organic solvent, under the condition of anhydrous and inert gas shielding, a compound V and L-2-aminobutanamide are subjected to a condensation reaction to obtain brivaracetam I. According to the method for preparing brivaracetam, brivaracetam is prepared through only four steps of reacting, the reaction steps are short, the total yield is high, aftertreatment steps and purifying methods are simple, a product with the de value larger than 99.80% can be prepared only through recrystallization, the grade API is reached, the production cost is low, and the method is suitable for industrial production. The formula is shown in the description.

The invention discloses a new method for synthesising L-alpha-aminobutyric acid with a high optical activity. The new method comprehensively applies alcohol dehydrogenase, threonine aldolase, threonine deaminase and L-amino acid dehydrogenase, and ethanol and glycine raw material are directly synthesised into L-alpha-aminobutyric acid by a 'one-pot' method. According to the method disclosed by the invention, L-alpha-aminobutyric acid is synthesised in one pot by virtue of the simple and easily available raw materials; the method has the advantages of being few in operation steps, environment-friendly, good in bio-safety and simple in equipment, and is beneficial to industrial large-scale production for L-alpha-aminobutyric acid with a high optical activity and L-alpha-aminobutyric acid series products.

The invention relates to a new preparation method of brivaracetam, and belongs to the field of chemical synthesis. According to the present invention, optically pure (R)-4-n-propyl-dihydrofuran-2(3H)-one is used as a raw material, and ring opening, halogenation, condensation, ring closure and other steps are performed to obtain the high-purity brivaracetam; and the preparation method has advantages of easily available raw materials, low cost, high total yield, high optical purity of the obtained product, simple reaction conditions and simple operation process.

The invention relates to the technical field of a drug, and concretely relates to an intermediate for preparing bictegravir and a preparation method thereof. The present invention provides two novel types of compounds and three routes for preparation of a compound (VI). Through substrate induction, chiral catalysis or synergistic effect of substrate induction and chiral catalysis, the stereoselectivity of a Diels-Alder reaction can be greatly improved, and a high chiral purity of a common intermediate (III) can be obtained; cut-out of N-O bond and reduction the double bond use catalytic hydrogenation, which can be environmentally friendly; the reaction conditions are mild, the yield is higher than the existing preparation method, the method is economic and effective, and is adapted to large-scale industrial production.

The invention discloses an azide and a preparation method thereof. The azide (I) can be used as a key raw material for preparing medicines with a 1,2,3-triazole structure, such as ticagrelor. The preparation method for the azide comprises the following step of: performing azidation reaction on an amino compound (II) and an azidation reagent (III) to obtain the azide (I). The preparation method is moderate in conditions, safe and environmentally-friendly, high in chemical yield, and especially capable of keeping the original absolute configuration and chiral purity.

The invention discloses a preparation method of (S, S)-2, 8-diazabicyclo[4, 3, 0]nonane and belongs to the field of the preparation method of a moxifloxacin intermediate. The preparation method comprises eight processes. A resolving process is carried out in initial of the preparation method, in the third process, an ester is resolved to form a chiral intermediate and then through a simple chemical reaction, the (S, S)-2, 8-diazabicyclo[4, 3, 0]nonane is prepared. The invention provides the preparation method utilizing an effective and economic synthesis route to prepare the high-chiral purity (S, S)-2, 8-diazabicyclo[4, 3, 0]nonane. The preparation method is free of an expensive resolving agent and greatly reduces a process cost. In the whole technology, the intermediate is not purified and the crude product can be directly used. The preparation method has simple processes and a high overall yield and can produce the product with chiral purity of 99%.

The invention discloses a method for synthesizing ursodeoxycholic acid (UDCA) and high-chiral-purity D-amino acid based on an enzyme-method coupling technology. The method comprises the following steps: putting chenodeoxycholic acid and alpha-ketonic acid into a solution system containing 7alpha-HSDH (Homoserine Dehydrogenase), DAADH and NADP (Nicotinamide Adenine Dinucleotide Phosphate) and carrying out enzyme catalysis reaction; separating a reaction solution by adopting an ultra-filtration membrane to obtain a concentrated mixed enzyme solution; regulating the pH (Potential of Hydrogen) ofa dialysis solution and crystallizing; filtering and separating to obtain 7-KLCA wet powder and filtrate; carrying out chromatographic treatment on the filtrate to obtain the D-amino acid; putting the7-KLCA wet powder into a solution system containing glucose, the NADP, the 7alpha-HSDH and GDH (Glutamate Dehydrogenase) and carrying out enzyme catalysis reaction; separating the reaction solution by adopting the ultra-filtration membrane to obtain the concentrated mixed enzyme solution; crystallizing, filtering and separating the dialysis solution, so as to obtain ursodeoxycholic acid. By adopting the method provided by the invention, UDCA and the high-chiral-purity D-amino acid can be obtained at the same time, the enzyme utilization rate is high, synthesis steps are simple and the cost isreduced; meanwhile, a metal reduction reagent and an organic solvent do not need to be added in a reaction process and conditions are mild; the method is environmentally friendly and is suitable forindustrial production.

The invention relates to the technical field of medical intermediates, in particular to a preparation method of a retegravir intermediate. The chemical name of the compound is (2R, 3R, 4R, 5R)-2-(4-aminopyrrole [2, 1-f] [1, 2, 4] triazine-7-yl)-3, 4, 5, 6-tetracarboxylic acid. The preparation method comprises the following steps: (1) in a solvent, carrying out asymmetric addition on 2, 3, 5-tribenzyloxy-D-ribose-1, 4-lactone to form (2R, 3R, 4R, 5R)-3, 4-bis (benzyloxy)-5-(((benzyloxy) methyl) tetrahydrofuran-2-nitrile; and 2) in a solvent, enabling (2R, 3R, 4R, 5R)-3, 4-bis (benzyloxy)-5-((benzyloxy) methyl)-2-hydroxytetrahydrofuran-2-nitrile to react with a hydroxyl activator and then react with 7-iodopyrrole[2, 1-f][1, 2, 4]triazine-4-amine to form (2R, 3R, 4R, 5R)-2-(4-aminopyrrole [2,1-f][1, 2, 4]triazine-7-yl)-3, 4-bis (benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-nitrile.

The invention belongs to the technical field of preparation of trans-menthyl-2, 8-diene-1-ol, and particularly relates to a synthesis process of trans-menthyl-2, 8-diene-1-ol. The synthesis process comprises the following steps: (1) taking limonene as a raw material, and carrying out lipase catalytic oxidation to prepare 1, 2-epoxy limonene; (2) ring-opening the 1, 2-epoxy limonene in the presenceof sodium borohydride and diphenyl diselenide to form limonene selenide; (3) forming selenium oxide under the action of an oxidizing agent by the limonene selenide and then carrying out elimination reaction to prepare the trans-menthyl-2, 8-diene-1-ol. According to the invention, the 1, 2-epoxy limonene is firstly prepared by a lipase catalysis method with high chiral selectivity, the purity of areaction intermediate is improved without a complex purification process, and the chiral purity of the final product trans-menthyl-2, 8-diene-1-ol is further improved.

According to one aspect of the present invention there is provided a substantially high purity D-(−)-N,N-diethyl-2-(α-naphthoxy)propionamide and a process for the manufacture of substantially higher purity D-(−)-N,N-diethyl-2-(α-naphthoxy)propionamide having chemical purity near about or above 95%, and chiral purity near about or more than 97%. According to another aspect of the invention is to provide an agrochemical compositions containing highly pure optically active D-(−)-N,N-diethyl-2-(α-naphthoxy)propionamide.

The invention provides a preparation method of an indoline derivative for synthesizing silodosin. Indoline is taken as a starting raw material and reacts with benzoic acid and 1-chloro-3-bromopropane to prepare a compound (1); a reaction is carried out in a Vilsmeier agent, and a formyl group in introduced to the 5th position to prepare a compound (2); the compound (2) and nitroethane undergoes an asymmetric Henry reaction in the catalysis of quinidine-copper acetate to prepare a compound (3); the compound (3) is subjected to acetylation through acetic anhydride to prepare a compound (4); a cyano group is introduced to the 7th position to prepare a compound (6); and two functional groups are reduced through palladium-on-carbon hydrogenation in one step to obtain a high-chiral-purity target compound: (R)-1-[1-(3-benzoyloxypropyl)-5-(2-aminopropyl)-7-cyano]indoline. In the early stage of the method, cheap quinidine is used to perform an asymmetric Henry reaction for introduction of chiral centers, thereby avoiding resolution in the latter stage. The method is reasonable in design, simple to operate, effectively improved in yield and reduced in cost, and therefore is suitable for massive production.

The invention discloses an industrial preparation method for lamivudine (3TC). The method is characterized in that: 5-hydroxyl-1,3-oxathiolane-2-carboxylic acid [(1<,>R, 2<,>S, 5<,>R)-5<,>-methyl-2<,>-(1-methylethyl) cyclohexyl] ester reacts with a acylating agent to obtain a acylate; the acylate and monosilylated acyl cytosine or monosilylated cytosine schiff's base are subjected to a glycosylation through a catalysis of lewis acid to obtain a 3TC intermediate, followed by reducing and deacylating or hydrolyzing and reducing to obtain the 3TC. The method provided by the present invention has advantages of simple, available and cheap raw materials, simple operation, safe production, high yield, less waste pollution, and is applicable for industrial production.

The invention discloses a preparation method of a baloxavir intermediate (R)-7-(benzyloxy)-3, 4, 12, 12a-tetrahydro-1H-[1, 4]oxazine[3, 4-c]pyrido[2, 1-f][1, 2, 4]-triazine-6, 8-diketone, and belongsto the field of drugs. According to the method, 3-benzyloxy-1-Boc amino-4-carbonyl-1, 4-dihydropyridine-2-carboxylic acid methyl ester and a chiral substrate L-serine ester are taken as raw materialsto carry out condensation reaction, substitution reaction and cyclization decarboxylation reaction to synthesize a baloxavir key intermediate (R)-7-(benzyloxy)-3, 4, 12, 12a-tetrahydro-1H-[1, 4]oxazine[3, 4-c]pyrido[2, 1-f][1, 2, 4]-triazine-6, 8-diketone and creatively develop the synthetic route for synthesizing the baloxavir intermediate (R)-7-(benzyloxy)-3, 4, 12, 12a-tetrahydro-1H-[1, 4]oxazine[3, 4-c]pyrido[2, 1-f][1, 2, 4]-triazine-6, 8-diketone. Compared to the traditional route, the preparation method has the advantages of the high yield, low cost, no need of resolution, the high chiral purity, convenience in industrialization and the like.