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Darstellung unsubstituierter und mit Chlor kernsubstitutierter [(Trifluormethyl)phenyl]phosphonsäuren nach einem geänderten Doak‐Freedman‐Verfahren
Author(s) -
Klumpp Egon,
Eifert Gyula,
Boros Peter,
Szulágyi János,
Tamás József,
Czira Gábor
Publication year - 1989
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19891221032
Subject(s) - chemistry , trifluoromethyl , catalysis , medicinal chemistry , chloride , organic chemistry , alkyl
Preparation of Unsubstituted and Chlorine‐Carrying [(Trifluoromethyl)phenyl]phosphonic Acids by a Modified Doak‐Freedman Procedure The performance of cuprous chloride and different phase‐transfer catalysts using the Doak‐Freedman procedure for preparing aromatic phosphonic acids have been compared by measurements of the evolved nitrogen volume in an eudiometer tube. In the investigated cases CuCl could well be exchanged by phase‐transfer catalysts. With the new method the already known [3‐(trifluoromethyl)phenyl]phosphonic acid, and the new [2‐chloro‐5‐(trifluoromethyl)phenyl]phosphonic acid, [4‐chloro‐3‐(trifluoromethyl)phenyl]phosphonic acid, as well as [2,4‐dichloro‐5‐(trifluoromethyl)phenyl]phosphonic acid were prepared. The good solubility of the phase‐transfer catalysts in water facilitates the separation of the catalysts from the reaction product, a property not observed for the copper compound. Other phosphonic acids may be prepared as well.