3.5- Dichlorosalicylic acid

The possibility for transport of Dicamba in subsurface soils, resulting in subsequent groundwater pollution, is potentially high. Both Dicamba and its initial transformation product 3,6-dichlorosalicylic acid have p2Ca values of 1.95 [392]. The high solubility of these weak acids at neutral to high pH makes it feasible for them to be mobile in lime treated or neutral pH soils. In the field, Dicamba (1) has been found to leach to a depth of 1 m over a 2-month period following application in a Missouri clay pan soil [296], (2) was discovered in approximately... 

Methanogenic enrichments resulted in O-demethylation of Dicamba to 3,6-dichlorosalicylic acid which was reductively dechlorinated to 6-chloro-salicylic acid and to salicylic acid, which was in turn further degraded to CH4 and C02. 

Plant Dicamba is hydrolyzed in wheat and Kentucky bluegrass plants to 5-hydroxy-2-methoxy-3,6-dichlorobenzoic acid and 3,6-dichlorosalicylic acid at yields of 90 and 5%, respectively. The remaining 5% was unreacted dicamba (Broadhurst et al., 1966). Dicamba was absorbed from treated soils, translocated in corn plants and then converted to... 

Smith, A.E. Breakdown of the herbicide dicamba and its degradation prodnct 3,6-dichlorosalicylic acid in prairie soils, J. Agric. FoodChem., 22(4) 601-605, 1974. 

This herbicide is discussed in methods for its codetermination with phenoxyacetic acid herbicides. Norris and Montgomery [198] described a procedure for the determination of traces of Dicamba and 2,4-D in streams after forest spraying. Dicamba and its metabolites (3,6-dichlorosalicylic acid and 5-hydroxydicamba) were determined gas chromatographically. 

Plants. Degradation rate varies greatly with species. In wheat, the major metabolite is 5-hydroxy-2-methoxy-3,6-dichlorobenzoic acid, while 3,6-dichlorosalicylic acid is also a metabolite... 

Soil. Microbial degradation occurs, the principal metabolite being 3,6-dichlorosalicylic acid. DT50, <14 days... 

Isofennhos. Exposure of soils to salicylic acid, the secondary hydrolysis product of isofenphos, resulted in enhanced degradation of isofenphos (Table IV). Nearly two-thirds of the applied isofenphos was converted to soil-bound residues in soil pretreated 3 and 4 times with salicylic acid. Seventy-eight percent of the applied isofenphos was recovered at the end of the 3-week incubation in the control treatment as compared with 34 to 65% in soils pretreated with salicylic acid. The ability of microbes to metabolize structurally similar compounds such as 3,5-dichlorosalicylate, 3,6-dichlorosalicylic acid (24), and 5-chlorosalicylate (25) to their benefit has been reported. The low microbial toxicity, relative availability (as discussed later in this chapter), and nutritive value of salicylic acid may contribute to its potential to condition soils for enhanced degradation of isofenphos. 

In water flea and flsh, the metabolite 3,6-dichlorosalicylic acid contributes more to the mixture effect than the parent compound despite its lower fraction, whereas the other two metabolites are insigniflcant. Note that the uncertainty related to estimating the (pH7) of the double negatively charged... 

Smith, A.E. Breakdown of the Herbicide Dicamba and Its Degradation Product 3,6-Dichlorosalicylic Acid in Prairie Soils, J. Agric. Food Chem., 22(4) 601-605 (1974). Smith, A.E. Degradation of the Herbicide Diclofop-Methyl in Prairie Soils, J. Agric. Food Chem., 25(4) 893-898 (1977). 

Soil Smith (1974) studied the degradation of C-ring- and " C-carboxyl-labeled dicamba in moist prairie soils at 25" C. After 4 weeks, >50% of the herbicide degraded to the principal products 3,6-dichlorosalicylic acid and carbon dioxide (Smith, 1974). 

Niclosamide was synthesized industrially by first chlorinating salicylic acid in chlorobenzene to yield 5-chlorosalicylic acid (I). Control of the amount of chlorine introduced is essential at this step, because an excess halogen leads to the formation of 3,5-dichlorosalicylic acid in addition to (I). When (I) is heated with 2-chloro-4-nitroaniline (II) in chlorobenzene (102— 104°C) in the presence of phosphorus oxychloride, niclosamide (III) is obtained [7]. 

Benzoic acid, 3,6-dichloro-2-hydroxy-, dipotassium salt. Benzoic acid, 3,6-dichloro-2-hydroxy-, dipotassium Dipotassium 3,6-dichlorosalicylate EINECS 273-146-8. 

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