The Chemical Structure and Herbicidal Activity of Alloxydimsodium and Related Compounds

Degradation of Cyclohexanedione Oxime Herbicides

“…These authors also noted the thermal degradation of this herbicide at 120º C, but they did not clarify whether such degradation is related to radiation exposure [29]. Regarding the thermal degradation of CHD herbicides, Soeda et al [38] also evaluated the transformation of alloxydim when it was heated to 30, 40 and 50 ºC in a dark incubator.…”

“…In this sense, studies of thermal degradation of alloxydim gave two oxazoles as transformation products at 120 ºC with a ratio between them of 3:2 [29]. The mechanism of the formation of these compounds involved the loss of alkoxy group, -OR 1 (Table 1), the Beckmann rearrangement and subsequent intramolecular cyclization.…”

“…Although the experimental design is not described, Iwataki and Hirono [29] observed that alloxydim was unstable and quantitatively decomposed when it was exposed to UV or sunlight. These authors also noted the thermal degradation of this herbicide at 120º C, but they did not clarify whether such degradation is related to radiation exposure [29].…”

“…As a first approach, Iwataki and Hirono (1979) [29] observed that alloxydim CHD herbicide was hydrolyzed in aqueous solution under acidic and basic conditions.…”

Chemical Behaviour and Herbicidal Activity of Cyclohexanedione Oxime Herbicides

“…3. These compounds show a keto-enol tautomerism, where the enolic forms (IV and VI) is generally predominant to the keto form (V) (Iwataki, 1992;Iwataki & Hirono, 1978). Thus, general formulas for this class of compounds are expressed as the enolic form.…”