53726-14-0Relevant articles and documents
Preparation method of L-2-aminobutanamide hydrochloride
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Paragraph 0020; 0026; 0029; 0035; 0038; 0044, (2021/06/21)
The invention relates to the technical field of preparation of chiral drug intermediates, and discloses a preparation method of L-2-aminobutanamide hydrochloride, which comprises the following steps: dropwise adding ethyl 2-bromobutyrate into stronger ammonia water, and carrying out chemical reaction in a closed container to prepare a prefabricated mixture; According to the preparation method of the L-2-aminobutanamide hydrochloride, ethyl 2-bromobutyrate is used as an initial raw material, and the medical intermediate L-2-aminobutanamide hydrochloride is prepared through ammonolysis and chiral resolution. Compared with the traditional preparation method, the preparation method adopts a chiral reagent (+)-mandelic acid with low raw material price and racemic 2-aminobutanamide hydrochloride to form diastereoisomers, the L-2-aminobutanamide hydrochloride is obtained through resolution by utilizing the difference of the dissolving properties of the diastereoisomers in ethanol, the optical purity and the chemical purity of the product are high, and the technical scheme has the advantages of mild reaction conditions, short reaction steps, high yield, stable product quality and easy realization of industrial production.
Method for splitting aminobutanamide by using ammonium hydrogen tartrate
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Paragraph 0024; 0029-0031; 0036-0038; 0043-0044, (2021/06/09)
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.
Method for synthesizing medicine for treating epilepsy by using L-2-aminobutanamide hydrochloride
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Paragraph 0048-0053; 0057-0061; 0064-0067; 0071-0074; ..., (2021/11/03)
The invention discloses a method for synthesizing a medicine for treating epilepsy by using L-2-aminobutanamide hydrochloride, and relates to the technical field of medicine synthesis, and the method comprises the following steps: under the protection of nitrogen, adding L-2-aminobutanamide hydrochloride and 4-chlorobutyrate into isopropyl alcohol, and reacting under the action of an alkaline substance and a catalyst, heating and refluxing to carry out nucleophilic substitution reaction and ring-closure reaction to prepare the levetiracetam. According to the method, the levetiracetam is synthesized by adopting a milder alkaline substance and a one-pot method, the operation is simple, the levetiracetam can be prepared without post-treatment, the levetiracetam obtained by the method is low in impurity content and high in chemical purity, the yield can reach 83.43% or above, and the purity reaches 99.6%.
Preparation method of (S)-(+)-2-aminobutanamide hydrochloride
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Paragraph 0032; 0038-0043; 0049-0054; 0060-0065; 0071-0076, (2020/08/02)
The invention discloses a preparation method of (S)-(+)-2-aminobutanamide hydrochloride, and relates to a preparation method of a levetiracetam key intermediate, and the method comprises the followingspecific steps: carrying out esterification reaction on L-2-aminobutyric acid serving as a starting material and thionyl chloride, and concentrating part of solvent after the reaction is finished; introducing ammonia gas to neutralize generated hydrogen chloride and residual thionyl chloride; and filtering, introducing ammonia gas, and carrying out an ammonolysis reaction to obtain the (S)-2-aminobutanamide hydrochloride after the treating is finished. According to the preparation method, the starting material is simple and easy to obtain, the one-pot method is adopted, the atom utilization rate is high, operation is easy and convenient, and the obtained product quality is high.
Method for preparing levetiracetam
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Paragraph 0077; 0080; 0083; 0087; 0089; 0093; 0095; 0099, (2020/02/14)
The invention relates to a method for preparing levetiracetam. The method comprises the following steps: reacting aminobutyric acid in lower alcohol and thionyl chloride to obtain an intermediate I; adding ammonia water to continue the reaction, and adding hydrochloric acid to adjust the pH value to about 3 to salify to obtain a salified intermediate II refined product; reacting the intermediate II in the presence of KOH in the presence of a catalyst and dichloromethane, and then adding 4-chlorobutyryl chloride to continuously react; adding water to hydrolyze, adjusting the pH to be weakly alkaline by using diluted hydrochloric acid, and crystallizing to obtain a levetiracetam crude product; decolorizing and crystallizing in ethyl acetate to obtain a refined product of levetiracetam. The invention also relates to the levetiracetam prepared by the method and pharmaceutical application thereof, for example, the levetiracetam can be used for treating or preventing epilepsy, Parkinson's disease, dyskinesia, migraine, tremor, idiopathic tremor, bipolar disorder, chronic pain, neuropathic pain, or bronchial, asthma or allergic diseases.
Production system of 2-aminobutanamide
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Paragraph 0069; 0093-0113, (2020/04/17)
The utility model provides a production system of 2-aminobutanamide, which comprises a first reactor, a second reactor, a third reactor, a fourth reactor, a fifth reactor and a sixth reactor, the second reactor is communicated with the first reactor and is used for reacting 2-hydroxybutyronitrile with an ammonia source to prepare 2-aminobutyronitrile; the third reactor is communicated with the second reactor and is used for carrying out hydrolysis reaction on the 2-aminobutyronitrile and strong base to prepare the 2-aminobutyramide. The device effectively reduces waste water, waste gas and waste residues, effectively reduces the use amount of hydrogen cyanide, improves the content of target products, and reduces the production cost.
Method for preparing levetiracetam
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Paragraph 0112; 0117-0119; 0129; 0133-0134, (2019/01/23)
The invention relates to the technical field of drug synthesis, and provides a method for preparing levetiracetam. The method includes the following steps: taking L-2-aminobutyric acid as a starting material, and preforming esterification with thionyl chloride to obtain (S)-2-methyl aminobutyrate hydrochloride; performing aminolysis reaction between the (S)-2-methyl aminobutyrate hydrochloride andammonia water to generate (S)-2-aminobutylamine hydrochloride; preforming acylation reaction between the(S)-2-aminobutylamine hydrochloride and the mixed solution of 4-chlorobutyryl chloride and dichloromethane; directly performing cyclization reaction between the intermediate product with the dichloromethane and tetrabutyl ammonium bromide to obtain a crude product of levetiracetam; and recrystallizing the crude product to generate the levetiracetam. The preparation method uses the easily-obtained starting material to ensure good reproducibility of the synthesis route, simple unit operationand economic accounting. The reaction in each step is easy to purify, the quality is controllable, and the reaction yield is greatly improved.
Preparation method and preparation system of 2-aminobutyramide
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Paragraph 0091; 0092-0110, (2019/10/01)
The invention provides a preparation method and a preparation system of 2-aminobutyramide. The preparation method comprises: (1) generating 2-hydroxybutyronitrile from hydrogen cyanide and n-propanalunder the action of a first catalyst; (2) adding an ammonia source and a second catalyst to the 2-hydroxybutyronitrile obtained in the step (1), and carrying out a reaction to generate 2-aminobutyronitrile; and (3) removing the excess ammonia from the reaction solution obtained in the step (2), adding a strong base and a third catalyst, and carrying out a hydrolysis reaction to obtain DL-2-aminobutanamide. According to the present invention, with the method and the system, the wastewater, the waste gas and the waste residue can be effectively reduced, the consumption of hydrogen cyanide can beeffectively reduced, the content of the target product can be increased, and the production cost can be reduced.
Preparation method of (S)-(+)-2-aminobutanamide hydrochloride
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Paragraph 0038; 0039; 0040, (2019/01/23)
The invention discloses a synthetic process of a chiral drug (S)-alpha-ethyl-2-oxo-pyrrolidine acetamide (levetiracetam) intermediate (S)-(+)-2-aminobutanamide hydrochloride which has anti-epileptic function. The synthetic process comprises the following steps: performing condensation on acetone cyanohydrins and n-propanal as initial raw materials in the presence of a catalyst to obtain 2-hydroxybutyronitrile; then carrying out a reaction with ammonia to obtain 2-amino butyronitrile; then carrying out hydrolysis to obtain 2-aminobutanamide; then splitting and salifying the 2-aminobutanamide to obtain a target product. The synthetic process is high in yield, the raw materials are low in price and are easily purchased on a large scale, and the synthetic process overcomes the defects that several existing processes need highly toxic and highly polluting raw materials and is simple in process operation and low in cost. Mother liquor after splitting is further racemized and split and is recycled repeatedly, so that the synthetic process is suitable for industrial production.
Continuous-flow protocol for the synthesis of enantiomerically pure intermediates of anti epilepsy and anti tuberculosis active pharmaceutical ingredients
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.
supporting information, p. 1552 - 1557 (2019/02/14)
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.
