Imazamox: A Quest for Polymorphic Modifications of a Chiral and Racemic Herbicide

The
structure–property relationships of new polymorphs of
the chiral herbicide imazamox were investigated by X-ray diffraction,
hot stage microscopy (HSM), and differential scanning calorimetry
(DSC). Four different polymorphs of imazamox­(R) were found. The relationship
between different crystal forms, relative thermal stability, and possible
conversions pathways was explored. Racemic imazamox, for which no
polymorphic modifications could be observed, was also characterized
in the solid state.