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Method for preparing gabapentin

A technology of gabapentin and gabapentin hydrochloride, which is applied in the field of gabapentin preparation, can solve the problems of dicyclohexylamine being expensive, unfavorable to industrial production, and uneconomical in industrial production, so as to avoid long production cycle, facilitate industrial production, and produce short cycle effect

Inactive Publication Date: 2004-10-27
曹桂东
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Prior art mainly prepares gabapentin aqueous solution by gabapentin hydrochloride, and its method mainly contains: a. remove hydrochloric acid by ion exchange resin and obtain gabapentin aqueous solution, its production cycle of this method is longer, is unfavorable for industrialized production; b. use NaOH, KOH or NH 4 Any aqueous solution in OH neutralizes gabapentin hydrochloride to the isoelectric point 7.14 of gabapentin, and then filters out salts by ion membrane to obtain gabapentin aqueous solution. The equipment requirements of this method are very high; c. utilize dicyclohexylamine It has a strong binding force with HCl, and the HCl in the gabapentin hydrochloride aqueous solution is taken away to form a dicyclohexylamine precipitate, which is filtered to obtain the gabapentin aqueous solution. The raw material dicyclohexylamine of this method is expensive and uneconomical for industrial production
Then, all three methods are to evaporate the moisture in the gabapentin aqueous solution to obtain the gabapentin crude product, and then refine the finished product, and their yield is between 72% and 82%, which is relatively low.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Embodiment 1: Get 20g of gabapentin hydrochloride, add 50g of ion-exchanged water to dissolve, add KHCO 3 , stirred for about 30 minutes, until no bubbles were produced, the solution was clear, and the KHCO 3 The pH value of the neutralized solution is between 7.2 and 7.5, directly heated with a water bath, the temperature of the material is controlled below 50°C, concentrated under reduced pressure until all of it becomes a solid, and then, add a small amount of methanol, and re-distill under reduced pressure to remove as much water as possible. Add 120ml of anhydrous methanol, heat to reflux, keep warm for 20 minutes, cool to room temperature, filter to remove most of the salt, recover methanol from the filtrate until it is all solid, add absolute ethanol and heat to reflux, cool to crystallize, filter, wash with ethanol , dried to obtain 16.2g of crude product; adding absolute ethanol to the crude product, heated to reflux, dissolved completely, cooled to room temper...

Embodiment 2

[0013] Embodiment 2: Get gabapentin hydrochloride 20g, add ion-exchanged water 50g to dissolve clear, add K 2 CO 3 , stirred for about 30 minutes, until no bubbles were produced, the solution was clear, and the K 2 CO 3 The pH value of the neutralized solution is between 7.2 and 7.5, directly heated with a water bath, the temperature of the material is controlled below 50°C, concentrated under reduced pressure until all of it becomes a solid, and then, add a small amount of methanol, and re-distill under reduced pressure to remove as much water as possible. Add 120ml of anhydrous methanol, heat to reflux, keep warm for 20 minutes, cool to room temperature, filter to remove most of the salt, recover methanol from the filtrate until it is all solid, add absolute ethanol and heat to reflux, cool to crystallize, filter, wash with ethanol , dried to obtain 16.1g of crude product, added absolute ethanol to the crude product, heated to reflux, dissolved completely, cooled to room t...

Embodiment 3

[0014] Embodiment 3: Get 20g of gabapentin hydrochloride, add 50g of ion-exchanged water to dissolve, add NaHCO 3 , stirred for about 30 minutes, until no bubbles were generated, the solution was clear, and the NaHCO 3 The pH value of the neutralized solution is between 7.2 and 7.5, directly heated with a water bath, the temperature of the material is controlled below 50°C, concentrated under reduced pressure until all of it becomes a solid, and then, add a small amount of ethanol, and re-distill under reduced pressure to remove as much water as possible. Add 120ml of anhydrous methanol, heat to reflux, keep warm for 20 minutes, cool to room temperature, filter to remove most of the salt, recover methanol from the filtrate until it is all solid, add absolute ethanol and heat to reflux, cool to crystallize, filter, wash with ethanol , dried to obtain 16.2g of crude product, added absolute ethanol to the crude product, heated to reflux, dissolved completely, cooled to room tempe...

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PUM

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Abstract

A process for preparing gabapentin from gabapentin hydrochloride includes dissolving gabapentin hydrochloride in ion exchanging water, regulating pH=7.14-8, stirring, heating to lowr than 60 deg.C by water bath, vacuum concentrating to become solid, adding organic solvent, vacuum distilling, thermally dissolving anhydrous organic solvent, cooling, filtering, distilling the filtrate for drying, dissolving in absolute alcohol, refluxing, cooling for crystallizing coarse gabapentin, dissolving in absolute alcohol, cooling, filtering concentrating, cooling for crystallizing, filtering and washing with absolute alcohol.

Description

technical field [0001] The invention relates to a method for preparing gabapentin, which belongs to the technical field of chemical synthesis, and in particular relates to an improvement of a process for preparing gabapentin by using gabapentin hydrochloride. Background technique [0002] Gabapentin, scientific name 1-(methylamino)cyclohexaneacetic acid, invented by Americans in 1977, is the main raw material of new anti-epileptic drugs and anti-anxiety drugs, used for the limitations of conventional anti-epileptic drugs that cannot be satisfactorily controlled or cannot be tolerated Adjuvant therapy for epileptic patients with epileptic seizures and partial seizures followed by generalized epilepsy. Gabapentin has recently been found to have the following new uses: a. It is effective for nausea caused by chemotherapy; b. It is effective for treating neuropathic pain syndrome; c. The US Food and Drug Administration (FDA) has approved it for the treatment of postherpetic neur...

Claims

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Application Information

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IPC IPC(8): C07C227/14C07C229/46
Inventor 曹桂东
Owner 曹桂东
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