Urea herbicides fenuron

More than 25 different substituted urea herbicides are currently commercially available [30, 173]. The most important are phenylureas and Cycluron, which has the aromatic nucleus replaced by a saturated hydrocarbon moiety. Benzthiazuron and Methabenzthiazuron are more recent selective herbiddes of the class, with the aromatic moiety replaced by a heterocyclic ring system. With the exception of Fenuron, substituted ureas (i.e., Diuron, Fluometuron, Fig. 10, Table 3) exhibit low water solubilities, which decrease with increasing molecular volume of the compound. The majority of the phenylureas have relatively low vapor pressures and are, therefore, not very volatile. These compounds show electron-donor properties and thus they are able to form charge transfer complexes by interaction with suitable electron acceptor molecules. Hydrolysis, acylation, and alkylation reactions are also possible with these compounds. 

SE Katz. Determination of the substituted urea herbicides linuron, monuron, diuron, neburon and fenuron in surface waters. J Assoc Off Anal Chem 49 452-456, 1966. 

TPNH) and oxygen to demethylate a number of closely related N,N-dimethylcarbamates (21). The same particulate system, however, exhibited a low order of activity on the urea herbicides monuron, diuron, and fenuron. Apparently, substitution of a nitrogen atom for the oxygen atom of the ester linkage to form the corresponding urea substantially decreased the velocity of the reaction. 

Of all the urea derivatives the herbicide fenuron (5) has the highest solubility in water and is the least adsorbed by the soil. Owing to its good water solubility, it is easily washed into the deeper layers of the soil. Absorbed through the roots it kills deep-rooted grass and broad-leaved weeds. It is also effective for the control of... 

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