Patent ID: 7820863
Filing Date: 2010-10-26
Classification: C07C

Abstract:
1. A process for preparing mesotrione, said process comprising: (i) Oxidation of 2-nitro-4-methylsulphonyl toluene (NMST) to give crude 2-nitro-4-methylsulphonyl benzoic acid (NMSBA); (ii) conversion of NMSBA to 2-nitro-4-methylsulphonyl benzoyl chloride- (NMSBC); (iii) reacting cyclohexanedione with 2-nitro-4-methylsulphonyl benzoyl chloride (NMSBC) to form an enol ester followed by a rearrangement process to give mesotrione; (iv) formation of mesotrione enolate in aqueous solution; (v) carrying out one or more purification processes on the mesotrione enolate formed in iv, and (vi) crystallizing the purified mesotrione enolate out of solution.