Pyrazole herbicides growth

The application of fluorinated furazan is rather limited for synthesis and reactivity. Most studied derivative is 3-amino-4-trifluoromethyl-l,2,5-oxadiazole, which is commercially available. Nevertheless, in recent years, some perspective applications have been envisaged. In the agrochemical field a large library (more than 300 derivatives) of A-(4-triflnoromethyl-l,2,5-oxadiazol-3-yl)benzamides 257 has been prepared and considered for herbicidal activity [ 140], while l-(4-fluoro-1,2,5-oxadiazol-3-yl)pyrazole derivatives 258 were claimed as herbicides and plant growth regulators (Fig. 14) [141]. 

In the whole plant studies, pyrazolate or pyrazoxyfen was treated to roots of rice and early watergrass when their second leaves were fully expanded. Both herbicides caused severe growth retardation and bleaching on the third leaves of early watergrass while no effect on rice (data not shown). 

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