| 摘要 |
PROCESS FOR MAKING PHOSPHONIC ACID DICHLORIDES Phosphonic acid dichlorides of the general formula I (I) are made by reacting thionyl chloride with a phosphonic acid dialkylester of the general formula II (II) and using, as the catalyst, a compound of the general formulae III, IV or V R1R2R3R4PX (III) R1R2R3P (IV) R1R2R3PO (V) in which R1, R2 and R3 each stand for identical or different alkyl groups or aryl groups having from 1 to 8 carbon atoms, X stands for chlorine or bromine, R4 has the same meaning as R1 through R3 or stands for chlorine or bromine. |
