Method for producing bis(fluoralkyl)phosphinic acid chlorides or fluoralkylphosphonic acid chlorides

A process for the preparation of a bis(fluoroalkyl)phosphinyl chloride or a fluoroalkylphosphonyl dichloride which comprises reacting:

• the corresponding bis(fluoroalkyl)phosphinic acid of the formula I
• R1R2P(═O)OH I,
• or a salt thereof,
• where
• R1 and R2 each stand, independently of one another, for straight-chain or branched alkyl groups CnF2n+1−yHy, where n denotes 1-12 and y denotes 0-5, but where y denotes 0, 1 or 2 when n =1 or 2, or
• the corresponding fluoroalkylphosphonic acid of the formula II
• R1P(═O)(OH)2 II,
• or a salt thereof,
• where R1 is as defined above,
• with an aryltetrachlorophosphorane as chlorinating agent,
• wherein the reaction is carried out at a temperature between −20° C. and 200° C.