Crystalline form of gamma-aminobutyric acid and preparation method thereof

Patent metadata

Field	Value
Publication number	US-10604474-B2
Application number	US-201616078008-A
Country	US
Kind code	B2
Filing date	Nov 7, 2016
Priority date	Nov 7, 2016
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

A method for preparing a new crystalline form of γ-aminobutyric acid, including the steps of: S1: preparing a γ-aminobutyric acid solution at an initial concentration of 0.5-1.0 g/mL by adding crude γ-aminobutyric acid to water; adding an additive to the γ-aminobutyric acid solution, raising the temperature to 50-80° C., stirring to produce a clear solution; and S2: obtaining a suspension by evaporating water from the product of S1 under reduced pressure and at 50-80° C.; obtaining a wet product by filtering the suspension; drying the wet product to obtain the new crystalline form of γ-aminobutyric acid. The preparation method of the new crystalline form of γ-aminobutyric acid is simple, easy to operate, low in energy consumption, economical and environmentally friendly. It is suitable for large-scale industrial production.

First claim

What is claimed is:

1. A new crystalline form of γ-aminobutyric acid, characterized in that the X-ray powder diffraction pattern of the new crystalline form has characteristic absorption peaks at diffraction angles 2θ of 14.8°±0.2°, 15.7°±0.2°, 17.6°±0.2°, 18.9°±0.2°, 21.0°±0.2°, 23.5°±0.2°, 27.5°±0.2°, 29.9°±0.2°, 31.4°±0.2°, 32.2°±0.2°, 33.3°±0.2°, 33.8°±0.2°, 35.6°±0.2°, 38.3°±0.2°.

2. The new crystalline form of γ-aminobutyric acid according to claim 1 , characterized in that the new crystalline form exhibits an endothermic characteristic peak at (220±2) ° C. in DSC analysis.

3. A method for preparing the new crystalline form of γ-aminobutyric acid according to claim 1 , characterized in that it includes the steps of:
S1: preparing a γ-aminobutyric acid solution at an initial concentration of 0.5-1.0 g/mL by adding crude γ-aminobutyric acid to water; adding an additive to the γ-aminobutyric acid solution, raising the temperature to 50-80° C., stirring the γ-aminobutyric acid solution to dissolve the solid substances in the solution; and
S2: obtaining a suspension by evaporating water from the product of S1 under reduced pressure and at 50-80° C.; obtaining a wet product by filtering the suspension; drying the wet product to obtain the new crystalline form of γ-aminobutyric acid;
wherein the additive in step S1 is one or more selected from sodium acetate, potassium acetate, and ammonium acetate; the mass ratio of the additive to the crude γ-aminobutyric acid is 0.1:100-0.5:100.

4. The method for preparing a new crystalline form of γ-aminobutyric acid according to claim 3 , characterized in that evaporating water under reduced pressure in step S2 is performed under a vacuum of 0.06-0.09 MPa.

5. The method for preparing a new crystalline form of γ-aminobutyric acid according to claim 4 , characterized in that in step S2, the volumetric ratio of water evaporated under reduced pressure to water present initially is 30:100 to 80:100, and evaporation time is 0.5 to 4 hours.

6. The method for preparing a new crystalline form of γ-aminobutyric acid according to claim 5 , characterized in that the drying in step S2 refers to drying at a temperature of 30-60° C. and under atmospheric pressure for 8-12 hours.

Assignees

• Nantong Licheng Biological Eng Co Ltd
• Univ Tianjin

Inventors

• Gong Junbo
• Zhao Kaifei
• Xi Haiyan
• Wu Xiaohua
• Hou Baohong
• Yin Qiuxiang
• Wang Jingkang
• Jin Feng
• Du Shichao
• Gu Qinqing
• Tang Shiping

Classifications

• C07B2200/13

  Crystalline forms, e.g. polymorphs · CPC title

• C07C229/08 Primary

  the nitrogen atom of the amino group being further bound to hydrogen atoms · CPC title

• C07C227/40

  Separation; Purification · CPC title