Abstract: The present invention relates to a process for the preparation of compounds of formula (I) wherein R1 and R2 are each independently of the other hydrogen or C1-C5alkyl and R3 is CF3 or CF2H, by a) reaction of a compound of formula (II) wherein R1 and R2 are as defined for formula (I), with at least one reducing agent to form a compound of formula (III) wherein R1 and R2 are as defined for formula (I), and b) reaction of that compound with at least one reducing agent to form a compound of formula (IV) wherein R1 and R2 are as defined for formula (I), and (c) reaction of that compound with a compound of formula (V) wherein Q is chlorine, fluorine, bromine, iodine, hydroxy or C1-C6alkoxy and R3 is as defined for formula (I), to form the compound of formula (I); and to novel intermediates for use in that process.

Abstract: A process for selectively controlling the crystallisation of thermodynamically stable Form (1) or kinetically stable Form (2) polymorphs of mesotrione from an aqueous mesotrione solution, said method comprising adjusting the pH of the mesotrione solutions to a value wherein said thermodynamically stable Form (1) or kinetically stable Form (2) mesotrione is ultimately obtained is disclosed.