| 摘要 |
<p>#CMT# #/CMT# Orthorhombic crystal modification (I) of tembotrione (2-(2-chloro-4-methylsulfonyl-3-(2,2,2-trifluoroethoxymethyl)phenylcarbonyl)-1,3-cyclohexanedione) is new. #CMT# : #/CMT# Independent claims are also included for: (1) two processes for producing (I); (2) herbicide comprising more than 80% (I) and optionally one or more metastable crystal modifications of tembotrione. #CMT#ACTIVITY : #/CMT# Herbicide. #CMT#MECHANISM OF ACTION : #/CMT# None given. #CMT#USE : #/CMT# (I) is useful as a herbicide for controlling unwanted plants, especially for controlling weeds in monocot crops (claimed). #CMT#ADVANTAGE : #/CMT# (I) is thermodynamically stable. #CMT#ORGANIC CHEMISTRY : #/CMT# Preparation: The first process comprises suspending or dissolving one or more metastable crystal modifications of tembotrione in a solvent, especially an alcohol or ketone, and treating the suspension or solution at 0-80[deg] C. The second process comprises grinding one or more metastable crystal modifications of tembotrione under a pressure of at least 5 bar. #CMT#EXAMPLE : #/CMT# Tembotrione (2 g) was dissolved in boiling acetone and the solution was cooled to room temperature at a rate of less than 20[deg] C/hour. The crystals were filtered and dried at temperatures below 60[deg] C. An oil dispersion of the product showed no signs of precipitation after storage for several weeks.</p> |
