Producing 5-fluoro-1-alkyl-3-fluoroalkyl-1H-pyrazol-4-carboxylic acid chloride (I), comprises (i) reacting 5-chloro-1-alkyl-3-fluoroalkyl-1H-pyrazol-4-carbaldehyde (II) with a fluorinating agent (III) optionally in the presence of a phase transfer catalyst to obtain 5-fluoro-1-alkyl-3-fluoroalkyl-1H-pyrazol-4-carbaldehyde (IV), and (ii) reacting (IV) with a chlorinating agent to obtain (I). Producing 5-fluoro-1-alkyl-3-fluoroalkyl-1H-pyrazol-4-carboxylic acid chloride of formula (I), comprises (i) reacting 5-chloro-1-alkyl-3-fluoroalkyl-1H-pyrazol-4-carbaldehyde of formula (II) with a fluorinating agent of formula (M +>；F ->；) (III) optionally in the presence of a phase transfer catalyst to obtain 5-fluoro-1-alkyl-3-fluoroalkyl-1H-pyrazol-4-carbaldehyde of formula (IV), and (ii) reacting (IV) with a chlorinating agent to obtain (I). R 1>；1-6C alkyl； R 2>；1-5C fluoroalkyl； M +>；Li +>；, Na +>；, K +>；, Cs +>；or Alk 4N +>；； and Alk : 1-4C alkyl. An independent claim is also included for producing (IV), comprising reacting (II) with (III) optionally in the presence of the phase transfer catalyst. [Image] ACTIVITY : Fungicide. No biological data given. MECHANISM OF ACTION : None given.
