Preparation of substituted 3-aryl-5-haloalkyl-pyrazoles having herbicidal activity

Processes for preparing substituted 3-aryl-5-haloalkyl-pyrazoles and, specifically, for preparing C1-5 alkyl esters of 5-[1-(C1-5 alkyl)-4-halo-5-(C1-3 haloalkyl)-1H-pyrazole-3-yl]-2,4-dihalo-benzoic acids such as isopropyl 5-[4-bromo-1-methyl-5-(trifluoromethyl)-1H-pyrazole-3-yl]-2-chloro-4-fluorobenzoate, are presented. The described processes include novel approaches for forming phenyl-diketones, forming and alkylating pyrazoles, brominating heterocyclic compounds, oxidizing alkyl-substituted benzene compounds, and esterifying carboxylic acids. These processes may be combined to prepare 3-aryl-5-haloalkyl pyrazoles, or alternatively, used in subcombinations or individually to prepare intermediates or other useful compounds.