Endothall

Endothall [45-73-2] Endothelins Endothia parasitica Endothion [2778-04-3] Endotoxin... 

Endothall 0.1 0.1 Stomach and intestinal problems Runoff from herbicide use... 

EMPICOL XEK/A , ethanol, 61 EMPILAN CDE/A2 , ethanol, 61 EMS Dottikon AG, 204 Endosulfan, 61 ENDOTAF , endosulfan, 61 Endothall, 61... 

Endohedral fullerenes, 12 230-231 chemistry of, 12 253 Endonucleases, artificial, 17 636 Endoperoxides, 18 442—443 Endopolygalacturonase, 11 598 Endo-receptors, convergent, 16 774 Endosseous dental implants, 8 344 Endothall (Aquathol Granular, Aquathol K), 13 315... 

Determination of Endothall in Drinking Water by Ion-Exchange Extraction, Acidic Methanol Methylation, and... 

Anthraquinone, see Anthracene 9,10-Anthraquinone, see Anthracene Aspartic acid, see Endothall Azobenzene, see Aniline... 

Biological. Incubation of C-ring labeled endothall (10 mg/mL) by Arthwbactersp., which was isolated from pond water and a hydrosol, in aerobic sediment-water suspensions revealed that after 30 d, 40% evolved as CO2. Glutamic acid was the major transformation product. Minor products were alanine, citric, and aspartic acids and unidentified products, some of which were tentativeiy identified as phosphate esters (Sikka and Saxena, 1973). In pond water treated with endothall (2 and 4 ppm), detectable levels were found after 7 d (Sikka and Rice, 1973). Biodegradation was rapid in an Ontario soil sample. After 1 wk, 70% of endothall added was converted to carbon dioxide (Simsiman et al, 1976). 

Chemical/Physical. Reacts with bases forming water-soluble salts. Above 90 °C, endothall is slowly converted to the anhydride (Windholz et al., 1983 Hartley and Kidd, 1987) and water (Humburg et al, 1989). Endothall is stable to light (Hartley and Kidd, 1987). 

Reinert, K.H. andRodgers, J.H., Jr. Influence of sediment types on the sorption of endothall. Bull. Environ. Contam. Toxicol, 32(5) 557-564, 1984. 

Sikka, H.C. and Rice, C.P. Persistence of endothall in aquatic environment as determined by gas-liquid chromatography, J. Agrlc. FoodChem., 21(5) 842-845, 1973. 

Sikka, H.C. and Saxena, J. Metabolism of endothall by aquatic microorganisms, J. Agric. Food Chem., 21 (3) 402-406,1973. 

Endothall is a structural analogue of cantharidin (Fig. 20). Its mode of action is apparently inhibition of protein phosphatase(s). A struc-ture/activity relationship study demonstrated that the presence of the oxygen bridge and the location of the two carboxylic groups play important roles in the activity of the molecules. The unusual 7-oxabicyclo[2.2.1]heptane ring of endothal is similar to that of cinmethylin, another natural product-like herbicide for which the mode of action has also eluded scientists for many years. 

Furan is readily hydrogenated, hence it is a source of commercial tetrahydrofuran (THF). Reaction with hydrogen sulfide over alumina produces thiophene. A recent patent describes a catalyst based on cobalt and molybdenum oxides supported on alumina for this reaction (105). Furan undergoes the Diels-Alder reaction with strong dienophiles. Hydrogenation of the product resulting from reaction with maleic anhydride, followed by hydrolysis and neutralization gives a herbicide, Endothall. 

Twenty-seven two-year-old scaleless hens were transported to Visalia, CA on October 1, 1979, housed in cages overnight with food and water provided ad lib, and exposed to field applications of DEF on October 2. Some birds were repeatedly treated over the next five days. The mature cotton fields (Diversified Farming Inc.) were sprayed from a ground vehicle that treated 8 rows simultaneously with DEF-6 (0.72 kg/l, 6 lb/gal Mobay Chemical Co.) at 0.37 gal/acre and Accelerate (amine salt of endothall (7-oxabicyclo (2.2.1) heptane-2,3-dicarboxylic acid, 0.06 kg/l, 0.5 lbs/gal) at 0.19 gal/acre in 25 gal water/acre. 

The best known of these defoliants are sodium chlorate which has the danger of starting fires, tributyl-phosphorotrithioite (merphos, Folex) its oxygenated relative tributylphosphorotri-thioite (DEF), and endothall (Accelerate). Recent research reports claim that amino methyl phosphonic acid and certain of its relatives were found to be more active than current commercial products. The best known desiccant used for defoliation of cotton is paraquat (1,1 -dimethyl-4,4 -bipyridinium) (8). 

Several materials have commercial use as abscission agents (6). In cotton, the products Accelerate (endothall), Folex (merphos) and DEF (oxidized form of merphos) have been identified as defoliants. Amid-thin continues to be used to thin fruit set. 3-CPA and Peach-thin 322, formerly used as peach thinners, serve as reminders of the disadvantages of highly specialized markets. RELEASE and PIK-OFF are under development as citrus abscission agents. 

Three fluorinated analogs of the herbicide endothall 55, that is, compounds 57-59, have been characterized by O NMR spectroscopy (cf Table 3). 

Table 3 NMR data for endothall 55, the anhydride 56, and the fluorinated analogs 57-59 [S In ppm 49MHz, 333K, CH3CN, external standard 1,4-dloxane)...

SYNS AQUATHOL 3,6-ENDOOXOHEXAHYDRO-PHTHALIC ACID ENDOTHALL ENDOTHAL TECHNICAL 3,6-ENDOXOHEXAHYDROPHTHALIC ACID 3,6-endo-EPOXY-l,2-CYCLOHEXANEDI-CARBOXYLIC ACID HEXAHYDRO-3,6-endo-OXYPHTHALIC ACID HYDOUT HYDROTHAD47 7-OXABICYCLO(2.2,l)HEPTANE-2,3-DICARBOXYLIC ACID RCRA WASTE NUMBER P088 TRI-ENDOTHAL... 

Chlorothal is slightly irritating to the eyes, while endothall has a Warning classification because of its moderate oral toxicity. 

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