申请人:ROTAM AGROCHEM INTERNATIONAL COMPANY LIMITED
公开号:US10316004B2
公开(公告)日:2019-06-11
A process for preparing clomazone is provided, the process comprising reacting 4,4-dimethyl-3-isoxazolidinone with 2-chlorobenzyl chloride in an aqueous medium in the presence of a base, in particular an alkali metal hydroxide. A method for preparing clomazone is also disclosed, the method comprising (a) crystallizing clomazone from solution in an organic solvent; and (b) isolating the resulting crystals. N-benzene is a particularly suitable solvent. Further, there is provided Form I crystalline 2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone (clomazone), wherein the polymorph Form I is characterized by at least one of the following properties:
(i) an X-ray powder diffraction pattern having characteristic peaks expressed in degrees 2θ(+/−0.20° θ) at one or more of the following positions: about 10.63, 16.07, 18.08, 19.11, 19.34, 21.20, 24.78 and 28.80; and
(ii) an infrared (IR) spectrum having a characteristic peak: at about 2967 and 2870 cm−1.
提供了一种制备氯马宗的工艺,该工艺包括在碱,特别是碱金属氢氧化物存在下,在水介质中使 4,4-二甲基-3-异噁唑烷酮与 2-氯苄基氯反应。还公开了一种制备氯马宗的方法,该方法包括:(a) 从有机溶剂的溶液中结晶氯马宗;(b) 分离得到的晶体。N 苯是一种特别合适的溶剂。此外,还提供了形式 I 结晶 2-[(2-氯苯基)甲基]-4,4-二甲基-3-异噁唑烷酮(氯马宗),其中形式 I 的多晶型具有以下至少一种特性:
(i) X 射线粉末衍射图样,在下列一个或多个位置具有以 2θ(+/-0.20° θ)度表示的特征峰:约 10.63、16.07、18.08、19.11、19.34、21.20、24.78 和 28.80;以及
(ii) 红外光谱,在约 2967 和 2870 cm-1 处有一个特征峰。