- Preparation method of glutaryl imide derivative
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The invention discloses a preparation method of a glutaryl imide derivative, which comprises the following steps: in a negative pressure state, dropwise adding acetic anhydride into molten 1, 1-cyclohexyl diacetic acid, and reacting to obtain 1, 1-cyclohexyl diacetic anhydride; adding ammonia water into an ammoniation kettle, dropwise adding 1, 1-cyclohexanediacetic anhydride to carry out ammoniation reaction, and adding hydrochloric acid to adjust the pH value, so as to obtain precipitated crystals, namely pentane valeric acid; adding pentane valeric acid, a toluene solvent and glacial aceticacid into the reaction kettle, heating, stirring, reacting, cooling, and carrying out suction filtration to obtain a filter cake; and adding the filter cake into ammonia water for soaking and stirring, carrying out suction filtration again, leaching with deionized water, and drying to obtain glutaryl imide. According to the preparation method of a glutaryl imide derivative, acetic anhydride and 1, 1-cyclohexyldiacetic acid are used as raw materials, so that the reaction efficiency is effectively improved, the product yield is increased, the production cost of the product is reduced, and producing benefits are improved.
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- Preparation method and application of 1-1 - cyclohexane - diacetic acid monoamide
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The invention discloses a preparation method of 1-1 - cyclohexane - diacetic acid monoamide (CDMA), which comprises an amidation reaction of 1, 1 - cyclohexanedicarboxylic acid anhydride and 1 and 1 - cyclohexane - diacetic acid monoamide ammonium salt in a non-polar solvent of non-benzene to obtain 1, 1 - cyclohexane - diacetic acid monoamide (CDMA). Alternatively, in the non-polar solvent of non-benzene, 1, 1 - cyclohexanedicarboxylic anhydride is reacted with ammonia to heat reflux to give 3, 3 - cyclopentanediimides. 3,3 - Cycloglutarimide is obtained 1 by untying a base water, 1 - cyclohexane - diacetic acid monoamide (CDMA) wherein, with 1, 1 - cyclohexanedicarboxylic acid as a starting material, dehydration is carried out under acid catalysis to give 1, 1 - cyclohexanedicarboxylic acid anhydride.
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- Preparation method of gabapentin intermediate
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The invention provides a preparation method of a gabapentin intermediate, and relates to the field of chemical organic synthesis. The preparation method comprises the following steps: taking cyanoacetic acid and cyclohexanone as raw materials, carrying out condensation, hydrolysis and decarboxylation reactions to obtain imide in an intermediate body, and further carrying out alkaline hydrolysis toobtain the intermediate cyclohexyl diacetate monoamide. The preparation method of the gabapentin intermediate provided by the invention has the advantages of readily available raw materials, mild reaction conditions, high safety factor, strong operability, simple process, easiness in industrialization, high product purity and stable quality.
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Paragraph 0076; 0082-0085; 0086-0091-0093; 0094; 0099-0101
(2021/04/03)
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- Process for the preparation of gabapentin
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The present invention relates to an improved process for the preparation of Gabapentin. The process also relates to a new process for the preparation of 1, 1-cyclohexane diaceitic acid monoamide (CDMA), which is a key intermediate for the preparation of Gabapentin.
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Paragraph 6; 7
(2019/09/17)
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- A process for synthesis of gabapentin
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The invention discloses a gabapentin synthesis technology. The gabapentin synthesis technology comprises the following steps of 1, preparing 1,1-cyclohexane diacetic anhydride, 2, preparing 3,3-cyclopentaneglutaramic acid, 3, preparing gabapentin hydrochloride, 4, adding the gabapentin hydrochloride into an oxalic acid solution, adjusting a pH value to 2-5, carrying out stirring, carrying out pressure reduction condensation to obtain filter cake, dissolving the filter cake in ethanol, carrying out stirring for dissolution, and carrying out pressure reduction drying to obtain fined gabapentin oxalate, and 5, adding the fined gabapentin oxalate into absolute ethanol, adjusting a PH value to 7-8, carrying out stirring, adding active carbon into the mixture, carrying out heating reflux, carrying out filtration, carrying out pressure reduction drying to obtain a gabapentin hydrate, adding the gabapentin hydrate into absolute ethanol, carrying out heating dissolution, carrying out cooling, carrying out filtration, concentrating the filtrate, carrying out cooling for crystal precipitation, carrying out filtration, carrying out washing by absolute ethanol and carrying out drying to obtain gabapentin. Gabapentin obtained by the gabapentin synthesis technology has high content and a high yield.
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- Synthesis and biological activities of Schiff bases of gabapentin with different aldehydes and ketones: A structure-activity relationship study
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A series of novel gabapentin derivatives 6a-k and 7a-f were synthesized, and their biological activities were determined. The chemical structures were confirmed by elemental analyses, UV-visible, FT-IR, and 1H NMR spectral studies. The structure-activity relationships (SAR) for anticonvulsant and antioxidant activities were discussed. Compounds 7a-f were evaluated for their possible anticonvulsant activity by Maximal Electroshock Seizure (MES) test, and their neurotoxic effects were determined by rotorod test. Majority of the compounds were active in MES tests. Compounds 7b and 7e showed good protective effect from seizure when compared to standard drug, phenytoin (100 mg/kg). The same compounds showed no neurotoxicity at the maximum dose administered (100 mg/kg). Most of the novel compounds showed DPPH radical scavenging activity, where compounds 6f, 6j, and 7a were the best radical scavengers (IC50 was about 60 μg/ml). Springer Science+Business Media, LLC 2010.
- Mallesha, Lingappa,Mohana, Kikkeri N.,Veeresh, Bantal
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scheme or table
p. 1 - 9
(2012/05/19)
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- Process For Synthesis Of Gabapentin
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A process for preparation of gabapentin comprising a step of obtaining 1,1-cyclohexane diacetic acid monoamide from 1,1-cyclohexane diacetic acid anhydride, wherein said reaction is characterized by the use of ammonia precursor or pre-generated ammonia-isopropanol solution. The invention further discloses preparation of gabapentin and isolation of gabapentin in polymorphic Form II with high yield and purity.
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Page/Page column 4
(2008/06/13)
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- PROCESS FOR THE PREPARATION OF GABAPENTIN
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The present invention relates to a process for the preparation of gabapentin and, more in particular, to a method of synthesis of 1,1-cyclohexane acetic acid monoamide, an intermediate used in the preparation of gabapentin, comprising the basic hydrolysis reaction of α,?-diaminocarbonyl-β,β-pentamethylene glutarimide.
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Page/Page column 12-13
(2008/06/13)
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- PROCESS FOR PREPARING CYCLOHEXANEDIACETIC ACID MONOAMIDE
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A new process is described for synthesising cyclohexanediacetic acid monoamide, a key compound in the synthesis of grabapentin precursors. The process of the invention is characterised by reacting cyclohexanone with cynoacetamide and immediately after, with a suitable malonic acid ester. A new intermediate (5-cyano-2,4-dioxo-3-azaspiro[5,5]undecane-1-carboxylic acid ester) is obtained which is convertible, under mild reaction conditions, into cyclohexanediacetic acid monoamide.
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Page/Page column 8-9
(2010/02/14)
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- PROCESS FOR THE PREPARATION OF GABAPENTIN
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The present invention relates to an improved process for the preparation of gabapentin and, more particularly, to an improvement of the preparation reaction of 1,1-cyclohexanediacetic acid monoamide, intermediate utilized in the preparation of gabapentin.
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Page/Page column 6-7
(2008/06/13)
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