- Method for splitting aminobutanamide by using ammonium hydrogen tartrate
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The present invention relates to the technical field of aminobutanamide resolution, and discloses a method for resolving aminobutanamide by using ammonium hydrogen tartrate, and the method comprises the following steps: taking 10-20 parts of ammonium tartrate, placing ammonium tartrate in a reaction flask, adding 20-40 parts of purified water, and performing stirring for 0.5-1.5 h to obtain an ammonium tartrate solution. According to the method for resolving aminobutanamide by using ammonium hydrogen tartrate, the ammonium hydrogen tartrate is used as a reactant and is subjected to resolution reaction with racemic 2-aminobutanamide, and an L-2-aminobutanamide ammonium hydrogen tartrate wet product obtained after the reaction is reacted with methanol and ammonia gas, so L-2-aminobutanamide and ammonium hydrogen tartrate can be separated out; the L-2-aminobutanamide liquid can be obtained, the ammonium hydrogen tartrate can be converted into the ammonium tartrate solid for recovery and storage, and the L-2-aminobutanamide solid can be used for splitting the aminobutanamide in the next ammonium hydrogen tartrate preparation so as to achieve the recovery and reutilization of the reactants, such that the production cost is reduced, and the low cost purpose is achieved.
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Paragraph 0024; 0029-0031; 0036-0038; 0043-0044
(2021/06/09)
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- Continuous-flow protocol for the synthesis of enantiomerically pure intermediates of anti epilepsy and anti tuberculosis active pharmaceutical ingredients
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Continuous-flow production of chiral intermediates plays an important role in the development of building blocks for Active Pharmaceutical Ingredients (APIs), being α-amino acids and their derivatives widely applied as building blocks. In this work we developed two different strategies for the synthesis of intermediates used on the synthesis of levetiracetam/brivaracetam and ethambutol. The results obtained show that methionine methyl ester can be continuously converted to the desired ethambutol intermediate by RANEY Nickel dessulfurization/reduction strategy whereas levetiracetam/brivaracetam intermediates could be synthesized by both RANEY Nickel (without H2) and Pd/C-H2 approach or by photochemical desulfurization.
- Aguiar, Renata M.,Le?o, Raquel A. C.,Mata, Alejandro,Cantillo, David,Kappe, C. Oliver,Miranda, Leandro S. M.,De Souza, Rodrigo O. M. A.
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supporting information
p. 1552 - 1557
(2019/02/14)
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- PROCESS FOR PREPARING BRIVARACETAM
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The present invention relates to a new process for preparing brivaracetam. (Ib)
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Page/Page column 7
(2017/06/23)
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- Preparation method for levetiracetam intermediate L-2-aminobutanamide hydrochloride
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The invention relates to a preparation method for a levetiracetam intermediate L-2-aminobutanamide hydrochloride. The method comprises the steps that n-propanal reacts with ammonia and hydrocyanic acid in a water solution under existing of ammonium chloride to prepare 2-amidogen butyronitrile, a certain amount of liquid ammonia and hydrocyanic acid are fed into mother liquor, and the mother liquor can be used indiscriminately for infinite times; the 2-amidogen butyronitrile is hydrolyzed in a 1% sodium hydroxide water solution to obtain 2-aminobutanamide, and water can be used indiscriminately for infinite times after being distilled; the 2-aminobutanamide is subjected to resolution to obtain L-2-aminobutanamide; salifying is carried out, and the L-2-aminobutanamide hydrochloride is obtained. The method has the advantages that the product quality is good, no waste water is produced in the production process, and the cost is low, and the preparation method is suitable for industrial production.
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Paragraph 0044; 0051; 0052; 0060; 0061; 0069; 0070
(2017/04/18)
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- Preparation method of S-2-aminobutanamide
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The invention provides a preparation method of S-2-aminobutanamide, comprising the steps of 1), reacting hydrogen cyanide, ammonia and n-propanal as materials to obtain 2-aminobutanenitrile; 2), separating a reacted liquid of step 1) by means of extraction to obtain an oil phase and a water phase, adding a catalyst and an alkali solution into the oil phase to carrying out hydrolysis, and reacting to obtain hydrolysate; 3), adding an acid or acid aqueous solution into the hydrolysate of step 2), separating to obtain an oil phase and a water phase, and separating the water phase to obtain S-2-aminobutanamide. The hydrogen cyanide, n-propanal and ammonia are reacted as materials to synthesize 2-aminobutanenitrile, the 2-aminobutanenitrile is hydrolyzed to directly obtain a target product, little byproducts are produced in reaction, and the content of the target product is high; little waste water and waste gas are produced in reaction, zero residue is produced, and there is no mass waste salts produced in the sodium cyanide process; the operation is simple, and product yield and purity are high.
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Paragraph 0024; 0027; 0029; 0032
(2017/02/09)
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- Processing technique of L-2-amino butyramide hydrochloride
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The invention relates to a processing technique of L-2-amino butyramide hydrochloride. The processing technique includes: using 2-chlorobutyric acid as a raw material and hexamethylenetetramine as a catalyst to prepare 2-aminobutyric acid; using L-tartaric acid to resolve 2-aminobutyric acid to obtain L-2-aminobutyric acid, acrylating L-2-aminobutyric acid to obtain L-2-aminobutyryl compound, and obtaining L-2-amino butyramide hydrochloride under the condition of ammonia water. The processing technique has the advantages that by the processing technique, reaction yield is increased, and byproducts are few. In addition, the processing technique is mild in reaction condition, easy in reaction control, low in cost, high in yield, high in product purity, low in equipment requirement and suitable for industrial production, and technique safety is improved greatly.
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Paragraph 0017; 0018
(2017/02/02)
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- An asymmetric synthesis of Levetiracetam
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An asymmetric synthesis of (S)-levetiracetam has been developed through application of a Strecker reaction using [(1S)- 1-(4-methoxyphenyl)ethyl]amine hydrochloride as a chiral auxiliary. Addition of propanaldehyde to a solution of sodium cyanide and [(1S)-1-(4-methoxyphenyl)ethyl]amine hydrochloride in the mixture of methanol and water at 25-30°C afforded diastereomerically pure 2-[2-(4-methoxyphenyl)-(S)-methylethyl-amino]-( S )-butyronitrile hydrochloride compound 4 . In this reaction cyanide group attack at less hindered side that is re-face of the imine intermediate gave the diastereomerically pure nitrile 4. Which upon hydrolysis in the presence of 6 M aqueous hydrochloride solution obtained enantiomerically pure (S )-2- aminobutyric acid hydrochloride 5, is a key intermediate for the (S)-levetiracetam. This intermediate further react with SOCl2 in presence of methanol formed S-2-amino methyl butyrate as in situ intermediate which on further ammonalysis in the presence of methnaolic ammonia as a solvent under ammonia pressure provided S-2-amino butyramide hydrochloride 6 which further condensed with 4-chlorobutyryl chloride 7 and followed by cyclization in the presence of potassium hydroxide, dichloromethane solvent used catalytic amount of tetra butyl ammonium bromide afforded crude (S)-levetiracetam 1, further recrystalization in the presence of ethyl acetate obtained pure (S)-levetiracetam 1.
- Raju, Veeramalla,Somaiah, Sripathi,Sashikanth, Suthrapu,Laxminarayan, Eppakayala,Mukkanti, Kagga
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p. 1218 - 1221
(2014/12/10)
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- Synthesis of tritium-labeled levetiracetam ((2S)-2-(2-oxopyrrolidin-1-yl) butanamide) with high specific activity
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A method for the preparation of [A3H]levetiracetam with a high specific activity of 98Ci/mmol (3.6TBq/mmol) is described. The radioligand proved to be highly useful for the labeling of specific levetiracetam binding sites in rat brain membrane preparations.
- Hildenbrand, Simone,Baqi, Younis,Mueller, Christa E.
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experimental part
p. 48 - 51
(2012/06/29)
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- Preparation of amino acid amides
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A process for making amino acid amides, comprising reacting an amino acid, or acid salt of an amino acid, with a halogenating agent, or with a substance that reacts with carboxylic acids to form a leaving group, to form an intermediate, then reacting the intermediate with ammonia. When the amino acid or acid salt is enantiomerically pure, the amide will be a stereoisomer. An amide made by the process can be used to form levetiracetam.
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Page/Page column 2
(2008/06/13)
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- PROCESS FOR PREPARING 2-OXO-1-PYRROLIDINE DERIVATIVES
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The present invention relates to a new process for preparing 2-oxo- I -pyrrolidine derivatives of general formula (I) wherein the substituents are as defined in the specification.
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Page/Page column 7-8
(2008/06/13)
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- PROCESS FOR PREPARING 2-OXO-1-PYRROLIDINE DERIVATIVES BY INTRAMOLECULAR ALLYLATION
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The present invention relates to a new process for preparing 2-oxo-1-pyrrolidine derivatives of general formula (I), comprising the cyclisation of an intermediate of general formula (II) wherein the substituents are as defined in the specification.
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Page/Page column 11-12
(2008/06/13)
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- Pharmaceutical compositions
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Compounds of formula II: wherein n is 0, 1 or 2, R1, R2, R3 and R4 are each separately selected from hydrogen, unsubstituted acyclic aliphatic hydrocarbon groups having a maximum of six carbon atoms and C1 6 alkyl groups substituted by a hydroxy group or a C1 6 alkoxy group, or one of R1 and R2 and one of R3 and R4 is hydrogen and the others are a trimethylene, tetramethylene or pentamethylene bridging group, and R5 as hydrogen or an unsubstituted acyclic aliphatic hydrocarbon group having a maximum of six carbon atoms, but with the provisos that (a) when n is 0 the combinations R1 = R2 = R3 = R4 = R5 = H and R1 = R2 = R3 = R5 = H, R4 = methyl are excluded, and (b) when n is 0, R1, R3 and R5 are each hydrogen, and each of R2 and R4 is other than hydrogen the compound is in other than the mesoor erythroconfiguration, or a salt thereof formed with a physiologically acceptable inorganic or organic acid, are of use in therapy, particularly as cardioprotective agents.
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