Crystal form of L-glufosinate and preparation method and use thereof
The present disclosure is directed to a crystal of L-glufosinate and a preparation method and use thereof. The crystal of L-glufosinate includes five crystal forms, namely crystal form A, crystal form B, crystal form C, crystal form D and crystal form E. These crystal forms show excellent effects in stability, hygroscopicity, storage, etc., which are beneficial to the preparation, separation and storage of herbicides, and at the same time have good solubility and good pharmacokinetics, which is further beneficial to improve the level and speed of herbicides to control weeds.
1 . A crystal of L-glufosinate, wherein the crystal of L-glufosinate is a crystal form D, the crystal form D is ammonium salt forms of L-glufosinate,
and the crystal form D has an X-ray powder diffraction pattern with characteristic peaks at 2θ 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°, and 25.716°±0.2°.
2 . The crystal of L-glufosinate according to claim 1 , wherein:
the X-ray powder diffraction pattern of the crystal form D further has one or more characteristic peaks at 2θ of 32.980°±0.2°, 35.920°±0.2°, and 39.509°±0.2°.
3 . The crystal of L-glufosinate according to claim 1 , wherein:
the X-ray powder diffraction pattern of the crystal form D has characteristic peaks at 2θ 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°.
4 . The crystal of L-glufosinate according to claim 1 , wherein:
the X-ray powder diffraction pattern of the crystal form D is as depicted in FIG. 7 .
5 . The crystal of L-glufosinate according to claim 1 , wherein:
a spectrum of the crystal form D determined by differential scanning calorimetry shows two endothermic peaks, onset temperatures of the two endothermic peaks are 161.84±2° C. and 199.46±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.
6 . The crystal of L-glufosinate according to claim 1 , wherein:
a spectrum of the crystal form D determined by differential scanning calorimetry is as depicted in FIG. 8 , and a combined spectrum of the crystal form D determined by differential scanning calorimetry and thermogravimetric analysis is as depicted in FIG. 9 .
7 . The crystal of L-glufosinate according to claim 1 , wherein:
the crystal form D is an anhydrous form.
8 . A preparation method of a crystal of L-glufosinate according to claim 1 , comprising:
adding L-glufosinate ammonium to an organic solvent;
heating to 65-90° C. and holding a temperature for a first time, then cooling down to 15 to 35° C. at a cooling rate of 1K between an external temperature and an internal temperature;
holding the temperature for a second time, precipitating a solid, filtering to obtain the solid; and
drying the solid obtained to give the crystal form D of L-glufosinate, wherein the organic solvent is methanol.
9 . The preparation method of the crystal of L-glufosinate according to claim 8 , wherein:
a feeding mass ratio of L-glufosinate ammonium to the organic solvent is 1:(1-20).
10 . The preparation method of the crystal of L-glufosinate according to claim 9 , wherein:
the feeding mass ratio of L-glufosinate ammonium to the organic solvent is 1:(1-10).
11 . The preparation method of the crystal of L-glufosinate according to claim 8 , wherein:
in the process of preparing the crystal form D of L-glufosinate, the holding temperature of the first time of temperature holding is 65-80° C., and a holding time of the first time of temperature holding is 1-15 h, and a holding time of the second time of temperature holding is 1 h-7 days.
12 . An herbicide composition comprising an active ingredient and a carrier, wherein the active ingredient comprises the crystal form D of L-glufosinate according to claim 1 in crystal form.