Crystal of l-glufosinate ammonium salt, preparation method therefor and use thereof

Abstract

A crystal of L-glufosinate ammonium salt, a preparation method therefor and an application thereof, the crystal of L-glufosinate ammonium salt comprising two novel crystal forms, namely novel crystal form D and crystal form E. On the basis of these two crystal forms having low hygroscopicity, the crystal forms not only have excellent stability, but also have good herbicidal effects, having a plant control effect on weeds such as sorrel, orange foxtail, sun spurge, bluegrass and other weeds can reach more than 85%.

Description

XRPD test was performed on the obtained crystal form, and the pattern was shown in Figure 1, there were characteristic peaks at diffraction angles 20 = 8.583°±0.2°, 17.202°, 18.398°, and 23.001°, and the 20 error range was ±0.2 degrees, confirming the existence of the new crystal form. Its x-ray powder diffraction data were shown in Table 1. Table 1: XRPD pattern Position [20 (°)] d spacing [A] BG Relative intensity [%] Relative area [%] FWHM 8.583 10.2935 10 29.7 24.8 0.135 17.202 5.1507 10 88.1 70.3 0.129 17.738 4.9960 5 52.5 82.7 0.255 18.398 4.8184 7 100 100 0.162 21.977 4.0411 3 17.8 13.2 0.12 22.721 3.9104 3 13.6 34.4 0.410 23.001 3.8634 2 61.9 86.9 0.227 25.716 3.4613 4 22 13 0.095 32.980 2.7137 3 19.5 20.6 0.171 35.920 2.4981 4 12.7 16.1 0.205 39.509 2.2790 2 12.7 21.0 0.267 Based on the standard sample without crystal water, the quantitative content was 99.01%, and the ammonium content by ion chromatography was 9.03%, which is basically the same as expected from the theoretical monoammonium salt (9.1 %). This crystal is an anhydrous form. It was found from the DSC curve that there were two endothermic peaks, the starting temperatures of the two endothermic peaks were 139.5 °C and 206.5 °C, respectively, the peak temperatures of the two endothermic peaks were 179.83 °C and 218.80 °C, respectively, and absorption of a large amount of heat occurred at 139.5 °C, indicating that when compared with other crystal forms, this crystal form is not easy to remove the ammonium group, and has better stability. It could be seen from the TGA spectrum that the weight of the crystal was basically unchanged below 139.5 °C, and started to decrease slowly from 139.5 °C, which is due to the heat absorption caused by the release of ammonia gas, and decreased rapidly from 206.5 °C, which may have undergone phase transition and decomposition. Embodiment 2: Preparation of crystal form E of L-glufosinate ammonium L-glufosinate ammonium (100 g, 0.48 mol, amorphous) was added to a mixed solution of water (40 g) and methanol (300 g), the system was heated to 68 °C, and the temperature was held for 10 h, then the system was cooled down to 50 °C at a cooling rate of Tj-Tr = 1K and the temperature was held for 1 h, then the system was cooled down to 25 °C at a cooling rate of Tj-Tr = 1K and the temperature was held for 24 h, then solid was separated out, filtered, and dried to give the crystal form E of L-glufosinate ammonium. XRPD test was performed on the obtained crystal form, and the pattern was shown in Figure 4, there were characteristic peaks at diffraction angles 20 = 8.884°±0.2°, 16.603°, 17.459°±0.2°, 18.101°, 18.658°, and 23.224°, and the 20 error range was ±0.2 degrees, confirming the existence of the new crystal form. Its x-ray powder diffraction data were shown in Table 2. Table 2: XRPD pattern Position [20 (°)] d spacing [A] BG Relative intensity [%] Relative area [%] FWHM 8.884 9.9453 3 100.0 1219 0.090 16.603 5.3349 2 11.4 222 0.145 17.459 5.0752 3 12.7 191 0.112 18.101 4.8967 3 93.0 1668 0.133 18.658 4.7519 3 17.0 279 0.122 19.513 4.5454 2 6.9 86 0.104 23.224 3.8268 2 14.4 285 0.147 33.221 2.6946 2 7.4 100 0.100 Based on the standard sample without crystal water, the quantitative content was 97%, and the ammonium content by ion chromatography was 8.81%, which is basically the same as expected from the theoretical monoammonium salt (8.82%). This crystal is an anhydrous form. It was found from the DSC curve that there were three endothermic peaks, the starting temperatures of the three endothermic peaks were 95.5 ± 2 °C, 147±2 °C, and 201 ± 2 °C, respectively; the peak temperatures of the three endothermic peaks were 113 ± 2 °C, 185.8±2 °C, and 226.5 ± 2 °C, respectively. Absorption of a small amount of heat occurred at about 95.5 °C and 147 °C, and absorption of a large amount of heat occurred at 201 °C, indicating that this crystal form is not easy to remove the ammonium group, and has better stability. It could be seen from the TGA spectrum that the weight of the crystal was basically unchanged below 95.5 °C, started to decrease slowly by 1.2%, which may be due to the influence of a small amount of impurities, and started to decrease slowly from 147 °C, which is due to the heat absorption caused by the release of ammonia gas, and decreased rapidly from 226.5 °C, which may have undergone decomposition. For the crystal form D and crystal form E of L-glufosinate ammonium, the data comparison of its high temperature stability were shown in Table 3. Table 3: Comparison of DSC Heat Absorption and Decomposition Temperatures Serial No. Crystal form Start of heat absorption Peak 1 Crystal form A in CN113480573A 110 °C 129 °C 2 Crystal form B in CN113480573A 115 °C 134 °C 3 Crystal form in CN113831364A 104 °C 115 °C 4 Crystal form D of L-glufosinate ammonium 139.5 °C 179.83 °C 5 Crystal form E of L-glufosinate ammonium 147 °C 185.833 °C Experiments show that the new crystal forms D and E of L-glufosinate ammonium have better high temperature stability than the ammonium salt crystal forms in the existing patent. Embodiment 3: Preparation of crystal form D of L-glufosinate ammonium L-glufosinate ammonium (100 g, 0.48 mol, the crystal form A in CN113480573) was added to methanol (300 g), the system was heated to 68 °C, and the temperature was held for 10 h, the system was cooled down to 35 °C at a cooling rate of Tj-Tr = 1K, the temperature was held for 24 h, and solid was separated out, filtered, and dried to give the crystal form D of L-glufosinate ammonium. XRPD test was also performed on the obtained solid, and the test pattern was substantially the same as depicted in Figure 1, indicating that the obtained solid is the crystal form D of L-glufosinate ammonium. Embodiment 4: Preparation of crystal form D of L-glufosinate ammonium L-glufosinate ammonium (100 g, 0.48 mol, the crystal form B in CN113480573) was added to methanol (300 g), the system was heated to 68 °C, and the temperature was held for 12 h, the system was cooled down to 25 °C at a cooling rate of Tj-Tr = 1K, the temperature was held for 24 h, and solid was separated out, filtered, and dried to give the crystal form D of L-glufosinate ammonium. XRPD test was also performed on the obtained solid, and the test pattern was substantially the same as depicted in Figure 1, indicating that the obtained solid is the crystal form D of L-glufosinate ammonium. Embodiment 5: Preparation of crystal form E of L-glufosinate ammonium L-glufosinate ammonium (100 g, 0.48 mol, the crystal form A in CN113480573) was added to a mixed solution of water (40 g) and methanol (300 g), the system was heated to 68 °C, and the temperature was held for 10 h, then the system was cooled down to 50 °C at a cooling rate of Tj-Tr = 1K and the temperature was held for 1 h, then the system was cooled down to 25 °C at a cooling rate of Tj-Tr = 1K and the temperature was held for 24 h, then solid was separated out, filtered, and dried to give the crystal form E of L-glufosinate ammonium. XRPD test was also performed on the obtained solid, and the test pattern was substantially the same as depicted in Figure 4, indicating that the obtained solid is the crystal form E of L-glufosinate ammonium. Embodiment 6: Preparation of crystal form E of L-glufosinate ammonium L-glufosinate ammonium (100 g, 0.48 mol, the crystal form B in CN113480573) was added to a mixed solution of water (40 g) and methanol (300 g), the system was heated to 68 °C, and the temperature was held for 10 h, then the system was cooled down to 50 °C at a cooling rate of Tj-Tr = 1K and the temperature was held for 1 h, then the system was cooled down to 25 °C at a cooling rate of Tj-Tr = 1K and the temperature was held for 24 h, then solid was separated out, filtered, and dried to give the crystal form E of L-glufosinate ammonium. 5       XRPD test was also performed on the obtained solid, and the test pattern was substantially the same as depicted in Figure 4, indicating that the obtained solid is the crystal form E of L-glufosinate ammonium. Embodiment 7: Hygroscopicity test 10       Experimental scheme: 100 g of solids were placed under different humidity for 48 h, and re-measured whether there was a significant change in their quality, and visually inspected whether there was a significant change in their appearance, so as to determine whether the crystal form had hygroscopicity, and the specific results were shown in Table 4. 15                                            Table 4 Serial No. Crystal form Weight Appearance Storage temperature Humidity Weight change (%) Appearance change 1 Embodiment 1 100.00 g White powder 25 °C 65 % +0.03 Unchanged 2 Embodiment 2 100.00 g White powder 25 °C 65 % +0.02 Unchanged 3 Embodiment 3 100.00 g White powder 25 °C 65 % +0.03 Unchanged 4 Embodiment 4 100.00 g White powder 25 °C 65 % +0.01 Unchanged 5 Embodiment 5 100.00 g White powder 25 °C 65 % +0.02 Unchanged 6 Embodiment 6 100.00 g White powder 25 °C 65 % +0.02 Unchanged 7 Embodiment 1 100.00 g White powder 25 °C 80% +1.12 Unchanged 8 Embodiment 2 100.00 g White powder 25 °C 80% +1.23 Unchanged 9 Embodiment 100.00 White 25 °C 80% +1.17 Unchanged 2022462454   30 Jun 2026 3 g powder 10 Embodiment 4 100.00 g White powder 25 °C 80% +1.12 Unchanged 11 Embodiment 5 100.00 g White powder 25 °C 80% +1.15 Unchanged 12 Embodiment 6 100.00 g White powder 25 °C 80% +1.18 Unchanged Experiments show that under the condition of low relative humidity, each crystal form has no obvious hygroscopicity. Under the condition of high relative humidity, each crystal form has very low hygroscopicity. 5 Embodiment 8: Stability test The crystals obtained in Embodiments 1 - 6 were stored for 48 days at 25 °C and 60 °C, respectively, the crystal form changes were re-measured, and the specific results were shown in Table 5. Table 5 Serial No. Crystal form Weight Temperature Humidity Crystal form Appearance Weight change (%) 1 Embodiment 1 100 g 25 °C 65 % Unchanged Unchanged +0.03 2 Embodiment 2 100 g 25 °C 65 % Unchanged Unchanged +0.02 3 Embodiment 100 g 25 °C 65 % Unchanged Unchanged +0.03 4 Embodiment 4 100 g 25 °C 65 % Unchanged Unchanged +0.01 5 Embodiment 5 100 g 25 °C 65 % Unchanged Unchanged +0.02 6 Embodiment 6 100 g 25 °C 65 % Unchanged Unchanged +0.02 7 Embodiment 1 100 g 60 °C 65 % Unchanged Unchanged +0.02 8 Embodiment 2 100 g 60 °C 65 % Unchanged Unchanged +0.01 9 Embodiment 3 100 g 60 °C 65 % Unchanged Unchanged +0.02 10 Embodiment 4 100 g 60 °C 65 % Unchanged Unchanged +0.01 11 Embodiment 5 100 g 60 °C 65 % Unchanged Unchanged +0.02 12 Embodiment 6 100 g 60 °C 65 % Unchanged Unchanged +0.02 10        Experiments show that crystal forms have excellent storage stability at 25 °C and 60 °C. Embodiment 9: Formulation preparation and field efficacy experiment The present disclosure is described in further detail below in conjunction with specific formulation preparation and field efficacy experiments, and the protected crystal forms of this patent meets the requirements of water preparations, and can also be developed into formulations such as single formulation and compound formulation. The following percentages are by weight. The combination of preparation processing and field efficacy test was adopted below. The test chemicals were provided by Jiangsu Sevencontinent Green Chemical Co., Ltd. Table 6: Glufosinate 10% aqueous solution Material name Formula ratio Glufosinate (crystal of L-glufosinate ammonium) 10 % Surfactant 3 % Water Supplement The above-mentioned formulations were prepared with the crystals of the embodiments 1-2 of the present disclosure, the crystal forms A and B of ammonium salt in CN113480573A and the crystal form A in the patent CN111065270A respectively for field efficacy experiments. It was detected that the physical and chemical properties of the aqueous solution products prepared by each crystal form were stable and met the needs of production and use, and at the same time, field experiments were carried out on different weeds. The dosage was 120 mL / mu. Referring to the "Pesticide-Guidelines for the field efficacy trials", 5 sites were investigated in each plot, each site was 1 square meter, and the types of weeds, the total number of plants, the symptoms of poisoning, the number of dead plants, etc. were recorded for each treatment 7 days after the treatment, and then the results of the plant control effect were counted, and the weed mortality was calculated and counted specifically. Weed mortality (%) = Number of dead plants treated Total number of plants treated *100% Table 7: Investigation results of plant control effect 7 days after treatment Treatment       Agent Preparation dosage (mL / mu) Plant control effect (%) Rumex Alopecurus aequalis Euphorbia helioscopia Bluegrass 1 Crystal form A in 120 100 80 80 80 CN113480573A Crystal form B in 2 CN113480573A Crystal form A in 120 100 85 80 80 3 CN111065270A Crystal form D of Embodiment 1 of 120 95 80 75 75 4 the present disclosure Crystal form E of Embodiment 2 of 120 100 86 85 85 5 the present disclosure 120 100 85 90 85 10 15 Conclusions: Compared with other crystal forms of the ammonium salt, the efficacy of the crystal forms D and E of the ammonium salt in this patent is obviously about 5% higher. The embodiments described above are only for illustrating the technical concepts and features of the present disclosure, and are intended to make those skilled in the art being able to understand the present disclosure and thereby implement it, and should not be concluded to limit the protective scope of this disclosure. Any equivalent variations or modifications according to the spirit of the present disclosure should be covered by the protective scope of the present disclosure. The endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to 2022462454   30 Jun 2026 I           1 include values close to these ranges or values. For ranges of value, between the end values of each range, between the end values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new ranges of value, and these ranges of value should be 5 considered as specifically disclosed herein. Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group 10 of integers or steps. The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the 15 common general knowledge in the field of endeavour to which this specification relates.

Claims

1. A crystal of L-glufosinate ammonium, wherein, the crystal of L-glufosinate ammonium is a crystal form D, which has an X-ray powder 5 diffraction pattern with characteristic peaks at 20 of 8.583°±0.2°, 17.202°±0.2°, 18.398°±0.2°, and 23.001°±0.2°.

2. The crystal of L-glufosinate ammonium according to claim 1, wherein, the X-ray powder diffraction pattern of the crystal form D of L-glufosinate ammonium 10 further has one or more characteristic peaks at 20 of 17.738°±0.2°, 21.977°±0.2°, 22.721°±0.2°, and 25.716°±0.2°.

3. The crystal of L-glufosinate ammonium according to claim 2, wherein, the X-ray powder diffraction pattern of the crystal form D of L-glufosinate ammonium 15 further has one or more characteristic peaks at 20 of 32.980°±0.2°, 35.920°±0.2°, and 39.509°±0.2°.

4. The crystal of L-glufosinate ammonium according to claim 1, wherein, the X-ray powder diffraction pattern of the crystal form D of L-glufosinate ammonium 20 has characteristic peaks at 20 of 8.583°±0.2°,  17.202°±0.2°,  17.738°±0.2°,18.398°±0.2°,   21.977°±0.2°,   22.721°±0.2°,   23.001°±0.2°,   25.716°±0.2°,32.980°±0.2°, 35.920°±0.2°, and 39.509°±0.2°.

5. The crystal of L-glufosinate ammonium according to claim 1, wherein, the 25 X-ray powder diffraction pattern of the crystal form D of L-glufosinate ammonium is as depicted in Figure 1.

6. The crystal of L-glufosinate ammonium according to claim 1, wherein, a spectrum of the crystal form D of L-glufosinate ammonium determined by 30 differential scanning calorimetry shows two endothermic peaks, starting2022462454   30 Jun 2026I           1temperatures of the two endothermic peaks are 139.5 ± 2 °C and 206.5 ± 2 °C, respectively, and a spectrum of the crystal form D determined by thermogravimetric analysis shows that a weight loss of 4.3±0.2% occurs when heated from 139.5±2 °C to 206.5±2 °C;57. The crystal of L-glufosinate ammonium according to claim 1, wherein, a spectrum of the crystal form D of L-glufosinate ammonium determined by differential scanning calorimetry is as depicted in Figure 2, and a combined spectrum of the crystal form D determined by differential scanning calorimetry and 10 thermogravimetric analysis is as depicted in Figure 3.

8. The crystal of L-glufosinate ammonium according to claim 1, wherein, the crystal form D of L-glufosinate ammonium is an anhydrous form.15        9. A crystal of L-glufosinate ammonium, wherein, the crystal of L-glufosinateammonium is a crystal form E, which has an X-ray powder diffraction pattern with characteristic peaks at 29 of 8.884°±0.2°,  16.603°±0.2°,  17.459°±0.2°,18.101°±0.2°, 18.658°±0.2°, and 23.224°±0.2°.20       10. The crystal of L-glufosinate ammonium according to claim 9, wherein,the X-ray powder diffraction pattern of the crystal form E of L-glufosinate ammonium further has one or more characteristic peaks at 29 of 19.513°±0.2° and 33.221°±0.2°.25       11. The crystal of L-glufosinate ammonium according to claim 9, wherein,the X-ray powder diffraction pattern of the crystal form E of L-glufosinate ammonium has characteristic peaks at 29 of 8.884°±0.2°,  16.603°±0.2°,17.459°±0.2°,  18.101°±0.2°,  18.658°±0.2°,  19.513°±0.2°,  23.224°±0.2°, and33.221°±0.2°.2022462454   30 Jun 2026112. The crystal of L-glufosinate ammonium according to claim 9, wherein, the X-ray powder diffraction pattern of the crystal form E of L-glufosinate ammonium is as depicted in Figure 4.

513. The crystal of L-glufosinate ammonium according to claim 9, wherein, a spectrum of the crystal form E of L-glufosinate ammonium determined by differential scanning calorimetry shows three endothermic peaks, starting temperatures of the three endothermic peaks are 95.5 ± 2 °C, 147±2 °C, and 201 ± 210   °C, respectively, and a spectrum of the crystal form E determined bythermogravimetric analysis shows that a weight loss of 1.2±0.2% occurs when heated from 95.5±2 °C to 147±2 °C, and a weight loss of 2.89±0.2% occurs when heated from 147±2 °C to 201±2 °C.15        14.   The crystal of L-glufosinate ammonium according to claim 9, wherein, acombined spectrum of the crystal form E of L-glufosinate ammonium determined by differential scanning calorimetry and thermogravimetric analysis is as depicted in Figure 5.20       15. The crystal of L-glufosinate ammonium according to claim 9, wherein,the crystal form E of L-glufosinate ammonium is an anhydrous form.

16. A preparation method of a crystal of L-glufosinate ammonium accordingto any one of claims 1-8, wherein, the preparation method of the crystal comprises:25 adding L-glufosinate ammonium to an organic solvent, heating to 65 - 90 °C and holding the temperature for the first time, then cooling down to -10 to 35 °C at a cooling rate of 1 to 5K between the external temperature and the internal temperature, holding the temperature for the second time, precipitating solid,2022462454   30 Jun 2026I           1filtering to obtain the solid, and drying the obtained solid to give the crystal form D of L-glufosinate ammonium.

17. A preparation method of a crystal of L-glufosinate ammonium according to 5 any one of claims 9-15, wherein, the preparation method of the crystal comprises: adding L-glufosinate ammonium to a mixed solvent of an organic solvent and water, heating to 65 - 90 °C and holding the temperature for the first time, cooling down to 40 to 60 °C at a cooling rate of 1 to 5K between the external temperature and the internal temperature, holding the temperature for the second time, then10 cooling down to -10 to 35 °C at a cooling rate of 1 to 5K between the external temperature and the internal temperature, holding the temperature for the third time, precipitating solid, filtering to obtain the solid, and drying the obtained solid to give the crystal form E of L-glufosinate ammonium.15       18. The preparation method of the crystal of L-glufosinate ammoniumaccording to claim 16 or 17, wherein, in the process of preparing the crystal form D or E of L-glufosinate ammonium, the organic solvent is selected from a group consisting of an alcohol solvent, a ketone solvent, a nitrile solvent, and combinations thereof.2019. The preparation method of the crystal of L-glufosinate ammonium according to claim 16 or 17, wherein, in the process of preparing the crystal form D or E of L-glufosinate ammonium, the feeding mass ratio of L-glufosinate ammonium to the organic solvent is 1: (1 - 20).2520. The preparation method of the crystal of L-glufosinate ammonium according to claim 17, wherein, in the process of preparing the crystal form E of L-glufosinate ammonium, the feeding mass ratio of water to the organic solvent is (0.05 - 0.3): 1.2022462454   30 Jun 202621. An herbicide composition, comprising an active ingredient and a carrier, wherein, the active ingredient comprises at least one of the crystal form D of L-glufosinate ammonium according to any one of claims 1-8 and the crystal form E5 of L-glufosinate ammonium according to any one of claims 9-15.

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