Gamma-aminobutyric acid hemihydrate crystal and preparation method thereof

Patent metadata

Field	Value
Publication number	US-10487044-B2
Application number	US-201616062716-A
Country	US
Kind code	B2
Filing date	Nov 11, 2016
Priority date	Nov 11, 2016
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

The present invention discloses a γ-aminobutyric acid hemihydrate crystal, its molecular formula is C4H9NO2.0.5H2O. It also discloses a method of preparing a γ-aminobutyric acid hemihydrate crystal, including first adding crude γ-aminobutyric acid to water to prepare a γ-aminobutyric acid suspension at an initial concentration of 1.2-2.0 g/mL; then stirring the suspension at a constant temperature of 5-10° C. for 6-12 hours, followed by filtering and drying to obtain the γ-aminobutyric acid hemihydrate crystal. The γ-aminobutyric acid hemihydrate crystal is stable, does not easily absorb moisture and agglomerate, and is convenient for further processing and use. The crystal has a large main particle size, uniform particle size distribution, high bulk density, good flowability, and a purity of ≥99%. The preparation method of the crystal according to the present invention is simple, easy to operate, highly efficient and low in energy consumption, and is suitable for large-scale industrial production.

First claim

What is claimed is:

1. A γ-aminobutyric acid hemihydrate crystal, wherein the molecular formula of the crystal is (C 4 H 9 NO 2 ) 2 ⋅H 2 O, the structural formula of the crystal is as follows:

2. The γ-aminobutyric acid hemihydrate crystal according to claim 1 , wherein the X-ray powder diffraction pattern of the crystal has characteristic absorption peaks at diffraction angles 2θ of 12.3°±0.2°, 24.5°±0.2°, 26.5°±0.2°, 29.6θ±0.2°, 31.6°±0.2°, 36.0°±0.2°, 37.5°±0.2°, and 39.5°±0.2°.

3. The γ-aminobutyric acid hemihydrate crystal according to claim 1 , wherein the X-ray powder diffraction pattern of the crystal has characteristic absorption peaks at diffraction angles 2θ of 12.3°±0.2°, 17.8°±0.2°, 20.6°±0.2°, 24.5°±0.2°, 25.4°±0.2°, 26.5°±0.2°, 28.5°±0.2°, 29.6°±0.2°, 31.6°±0.2°, 34.6°±0.2°, 36.0°±0.2°, 37.5±0.2°, 38.4°±0.2°, 39.5°±0.2°.

4. The γ-aminobutyric acid hemihydrate crystal according to claim 3 , wherein the crystal exhibits a water loss of 7.9% to 8.1% over 120-180′C in TGA analysis; the crystal exhibits an endothermic characteristic peak at (225±2) ° C. in DSC analysis.

5. A method of preparing the γ-aminobutyric acid hemihydrate crystal according to claim 1 , comprising the steps of:
S1: adding crude γ-aminobutyric acid to water to prepare a γ-aminobutyric acid suspension at an initial concentration of 1.2 g/mL to 2.0 g/mL; and
S2: stirring the product of S1 at a constant temperature between 5-10° C. for 6-12 hours, filtering and drying to obtain the γ-aminobutyric acid hemihydrate crystal.

6. The method of preparing the γ-aminobutyric acid hemihydrate crystal according to claim 5 , wherein step S2 comprises stirring the product of S1 at a constant temperature of 5° C. for 12 hours.

7. The method of preparing the γ-aminobutyric acid hemihydrate crystal according to claim 5 , wherein step S2 comprises stirring the product of S1 at a constant temperature of 5° C. for 9 hours.

8. The method of preparing the γ-aminobutyric acid hemihydrate crystal according to claim 6 , wherein the drying in step S2 is drying at a temperature between 20-35° C. and a vacuum between 0-0.08 MPa for 8-12 hours.

9. The method of preparing the γ-aminobutyric acid hemihydrate crystal according to claim 8 , wherein the drying in step S2 is drying at a temperature of 35° C. and a vacuum of 0.08 MPa for 12 hours.

10. The method of preparing the γ-aminobutyric acid hemihydrate crystal according to claim 8 , wherein the drying in step S2 is drying at a temperature of 35° C. and at atmospheric pressure for 8 hours.

11. The γ-aminobutyric acid hemihydrate crystal according to claim 2 , wherein the X-ray powder diffraction pattern of the crystal has characteristic absorption peaks at diffraction angles 2θ of 12.3°±0.2°, 17.80±0.2°, 20.6°±0.2°, 24.5°±0.2°, 25.4°±0.2°, 26.5°±0.2°, 28.5°±0.2°, 29.6°±0.2°, 31.6°±0.2°, 34.6°±0.2°, 36.0°±0.2°, 37.5°±0.2°, 38.4°±0.2°, 39.5°±0.2°.

12. The γ-aminobutyric acid hemihydrate crystal according to claim 11 , wherein the crystal exhibits a water loss of 7.9% to 8.1% over 120-180° C. in TGA analysis; the crystal exhibits an endothermic characteristic peak at (225±2) ° C. in DSC analysis.

13. The method of preparing the γ-aminobutyric acid hemihydrate crystal according to claim 7 , wherein the drying in step S2 is drying at a temperature between 20-35° C. and a vacuum between 0-0.08 MPa for 8-12 hours.

14. The method of preparing the γ-aminobutyric acid hemihydrate crystal according to claim 13 , wherein the drying in step S2 is drying at a temperature of 35° C. and a vacuum of 0.08 MPa for 12 hours.

15. The method of preparing the γ-aminobutyric acid hemihydrate crystal according to claim 13 , wherein the drying in step S2 is drying at a temperature of 35° C. and at atmospheric pressure for 8 hours.

Assignees

• Nantong Licheng Biological Eng Co Ltd
• Univ Tianjin

Inventors

• Gong Junbo
• Gu Qinqing
• Zhao Kaifei
• Li Jiangbo
• Hou Baohong
• Yin Qiuxiang
• Wang Jingkang
• Sun Yi
• Du Shichao
• Pan Xin
• Liu Zhongshi

Classifications

• C07C229/08

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

• C07B2200/13

  Crystalline forms, e.g. polymorphs · CPC title

• C07C227/42 Primary

  Crystallisation · CPC title