DEP (Falone&{2,4-Dichlorophenoxyethyl phosphite | 
In the presence of moisture, DEP underwent hydrolysis with formation of 
inorganic phosphate and 2,4-dichlorophenoxyethanol. This could then undergo 
oxidation to 2,4-D (44, 1288). 
-CHy~CHy0 -CH2-CH20H 
7 1 
3 2,4-Dichloro- 
DEP 

2,4-D 
phenoxy Ethanol 
Dexon [(p-Dimethylaminobenzenediazo sodium sulfonate) ] 
Rhizoctonia and sugar beets have a mitochondrial system that decomposes 
dexon in the presence of DPNH (1410). Studies with cl4-1abeled dexon and 
Aphanomyces cochloides Drechs. showed that it was taken up by roots and 
translocated to hypocotyls. Much of the label was not extractable in aqueous 
i methanol. Radioautographs of root extracts showed that dexon was rapidly 
i converted into at least four unidentified C!*-labeled compounds (657). 
Studies with aqueous solutions of dexon suggested a two stage decompo- 
sition in the presence of light and air: (1) photochemical reduction of 
the diazonium group and evolution of nitrogen; (2) oxidation followed by 
polymerization of the reaction products. During these developments, the 
solution changes in color from yellow to pink and deepens to purple. 
Spectrophotometric studies indicated that any p-dimethylaminophenol formed 
was rapidly converted to other compounds (658). 
141 

