Dichlorovinylation

In the body, metrifonate converts to the active metaboUte dichlorvos, (2,2-dichlorovinyl dimethyl phosphate), which is responsible for the inhibition of the enzyme acetylcholinesterase in the susceptible worm. This effect alone is unlikely to explain the antischistosomal properties of metrifonate (19). Clinically, metrifonate is effective only against infection caused by S. haematobium. Metrifonate is administered in three doses at 2-wk intervals (17). The dmg is well tolerated. Side effects such as mild vertigo, nausea, and cramps are dose-related. This product is not available in the United States. The only manufacturer of metrifonate is Bayer A.G. of Leverkusen, Germany. 

Variations in the reaction temperature and in the proportions of the ketone and PCI5 were appreciably reflected in the ratio of the amounts of compound 9 obtained in the first stage to the total content of 7 and 8 and then proportionally in the composition of the final products. In the interaction of the ketones with PCI5, an excess of the latter and high temperature make the anomalous reactions more significant. 4-(l,2-Dichlorovinyl)-3,5-dimethyl-l//-pyrazole (9) was obtained individually by the action of more than a twofold excess of PCI5 on the acetylpyrazole 6 at 80°C in 50% yield. Under the influence of NaNHa in liquid NH3, dichloroethy-lene 9 was converted into chloroacetylene 10 by loss of a molecule of HCl (yield 77%) (Scheme 28). 

In addition, it was clear that the presented scheme does not exhaust all the possible paths of anomalous chlorination. Thus, 4-acetyl-l,3,5-trimethylpyrazole with 4-5 moles of phosphorus pentachloride gave mainly 4-Q ,/3-dichlorovinyl-5-chloromethyl-l,3-dimethylpyrazole, and its precursor (according to GLC data) was the dichloride. It could be possible that in the case of 4-chlorovinyl derivatives of pyrazole the chlorination at the p position is facilitated by the electron-donating characteristics of the 4-pyrazolyl radical (86TH1). 

Although trichloroethylene itself may not be genotoxic, several of its metabolites are reactive and potentially genotoxic compounds (Miller and Guengerich 1982). Several isomers of 1,2-dichlorovinyl-cysteine, a product of trichloroethylene metabolism in the kidney, are mutagenic in the in vitro Ames assay... 

Bimer G, Vamvakas S, Dekant W, et al. 1993. Nephrotoxic and genotoxic N-acetyl-S-dichlorovinyl-L-cysteine is a urinary metabolite after occupational 1,1,2-trichloroethene exposure in humans Implications for the risk of trichloroethene exposure. Environ Health Perspect 99 281-284. 

Commandeur JNM, Vermeulen NPE. 1990a. Identification of N-acetyl-S-(2,2-dichlorovinyl) and N-acetyl-S-(l,2-dichlorovinyl)-L-cysteine as two regioisomeric mercapturic acids of trichloroethylene in the rat. Chem Res Toxicol 3 212-218. 

Dekant W, Metzler M, Henschler D. 1986a. Identification of S-l,2-dichlorovinyl- N-acetyl-cysteine as a urinary metabolite of trichloroethylene A possible explanation for its nephrocarcinogenicity in male rats. Biochem Pharmacol 35 2455-2458. 

Elfarra AA, Jakobson 1, Anders MW. 1986. Mechanism of S-(l,2-dichlorovinyl)glutathione-induced nephrotoxicity. Biochem Pharmacol 35 283-288. 

Eyre RJ, Stevens DK, Parker JC, et al. 1995b. Renal activation of trichloroethene and S -(l,2-dichlorovinyl)-L-cysteine and cell proliferative responses in the kidneys of F344 rats and B6C3F, mice. J Toxicol Environ Health 46 465-481. 

McKinney LL, Weakley FB, Eldridge AC, et al. 1957. S-(dichlorovinyl)-L-cysteine an agent causing fatal aplastic anemia in calves. J Am Chem Soc 79 3932-3933. 

Benzotriazole-related methodology publications appeared in 2006. Reaction of 1-formylbenzotriazole with triphenylphosphine/carbon tetrachloride afforded l-(2,2-dichlorovinyl)benzotriazole, where lithiation followed addition of electrophiles gave a variety of functionalized M-(ethynyl)benzotriazoles <06T3794>. Novel mono- and symmetrical di-/V-hydroxy- and IV-aminoguanidines were readily prepared from the reaction of diverse hydroxylamines or hydrazines with reagent classes di(benzotriazol-l-yl)methanimine, (bis-benzotriazol-1 -y 1-methy lene)amines, benzotriazole-1 -carboxamidines, benzotriazole-1 -... 

MWNTs favored the detection of insecticide from 1.5 to 80 nM with a detection limit of InM at an inhibition of 10% (Fig. 2.7). Bucur et al. [58] employed two kinds of AChE, wild type Drosophila melanogaster and a mutant E69W, for the pesticide detection using flow injection analysis. Mutant AChE showed lower detection limit (1 X 10-7 M) than the wild type (1 X 10 6 M) for omethoate. An amperometric FIA biosensor was reported by immobilizing OPH on aminopropyl control pore glass beads [27], The amperometric response of the biosensor was linear up to 120 and 140 pM for paraoxon and methyl-parathion, respectively, with a detection limit of 20 nM (for both the pesticides). Neufeld et al. [59] reported a sensitive, rapid, small, and inexpensive amperometric microflow injection electrochemical biosensor for the identification and quantification of dimethyl 2,2 -dichlorovinyl phosphate (DDVP) on the spot. The electrochemical cell was made up of a screen-printed electrode covered with an enzymatic membrane and combined with a flow cell and computer-controlled potentiostat. Potassium hexacyanoferrate (III) was used as mediator to generate very sharp, rapid, and reproducible electric signals. Other reports on pesticide biosensors could be found in review [17],... 

Analysis of the conformational and structural stability of N-vinylnitrone CH2=CH—N(0)=CH2 and /V-(2,2-dichlorovinyl)nitrone CCl2=CH-N(0) = CH2 with DFT-B3LYP and MP2 methods revealed that they have a planar structure resulting from the apparent conjugation between C=C and N=C bonds. 

Transfluthrin (30) [39] is a compound obtained by esterification of dichlorovinyl chrysanthemic acid with 2,3,5,6-tetrafluolobenzylalcohol. With very high insecticidal potency against mosquitoes and flies, it is used as a household insecticide however, as the promotion activity of the compound is known, its use should be restricted to preparations in which the issues of safety for humans and pets have been resolved. 

Bicker W, Kacprzak K, Kwit M, Lammerhofer M, Gawronski J, Lindener W (2009) Assignment of absolute configurations of permethrin and its synthon 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid by electronic circular dichroism, optical rotation, and X-ray crystallography. Tetrahedron Asymmetry 20 1027-1035... 

Anderson PM, Schultze MO. Cleavage of S-(l,2-dichlorovinyl)-L-cysteine by an enzyme of bovine origin. Arch Biochem Biophys 1965 lll(3) 593-602. 

Hassall, C.D., Gandolfi, A.J. and Brendel, K. (1983). Correlation of the in vivo and in vitro renal toxicity of S-(1.2-dichlorovinyl)-L-cysteine. Drug. Chem. Toxicol. 6 507-520. 

Zhang, G. and Stevens, J.L. (1989). Tansport and activation of 5-(l, 2-dichlorovinyl)-L-cysteine andA-acetyl-S-(l,2-dichlorovinyl)-L-cysteine in rat kidney proximal tubules. Toxicol. Appl. Pharmacol. 100 51-61. 

R. Traverso, A. Moretto, M. Lotti, Human Serum A -Esterases. Hydrolysis of o,o-Dimethyl-2,2-dichlorovinyl Phosphate , Biochem. Pharmacol. 1989, 38, 671-676. 

Dichlorovinyl dimethyl phosphoric acid ester, see Dichlorvos... 

Dimethyl-3-(3.4-dichlorophenyl)urea, see Diuron Dimethyl dichlorovinyl phosphate, see Dichlorvos Dimethyl-2.2-dichlorovinyl phosphate, see Dichlorvos 0,0-Dimethyl-0-(2.2-dichlorovinyl)phosphate. see Dichlorvos... 

Dichlorovinyl acid, see Permethrin cis-Dichlorovinyl acids, see Permethrin frans-Dichlorovinyl acids, see Permethrin els- (Dichlorovinyl) dimethyl cyclopropanecarboxy lie acid, see Permethrin... 

In lake water, permethrin degraded more rapidly than in flooded sediments to trans- and a 5-(dichlorovinyl)dimethylcyclopropanecarboxylic acid. The cis- isomer was more stable toward biological and chemical degradation than the trans isomer (Sharom and Solomon, 1981). 

Plant. Metabolites identified in cotton leaves included /ra/js-hydroxypermethrin, 2 hydroxypermethrin, 4 -hydroxypermethrin, dichlorovinyl acid, dichlorovinyl acid conjugates, hydroxydi-chlorovinyl acid, hydroxydichlorovinyl acid conjugates, phenoxybenzyl alcohol, and phenoxy-benzyl alcohol conjugates. Degradation of permethrin was mainly by ester cleavage and conjugation of the acid and alcohol intermediates (Gaughan and Casida, 1978). 

Photolytic. Photolysis of permethrin in aqueous solutions containing various solvents (acetone, hexane, and methanol) under UV light (1 >290 nm) or on soil in natural sunlight initially resulted in the isomerization of the cyclopropane moiety and ester cleavage. Photolysis products identified were 3-phenoxybenzyldimethyl acrylate, 3-phenoxybenzaldehyde, 3-phenoxybenzoic acid, mono-chlorovinyl acids, cis- and fra/is-dichlorovinyl acids, benzoic acid, 3-hydroxybenzoic acid, 3-hydroxybenzyl alcohol, benzyl alcohol, benzaldehyde, 3-hydroxybenzaldehyde, and 3-hydroxybenzoic acid (Holmstead et ah, 1978). 

Mattson, A.M., Spillane, J.T., and Pearce, G.W. Dimethyl 2,2-dichlorovinyl phosphate (DDVP), an organic phosphorus compound highly toxic to insects, J. Agric. Food Chem., 3(4) 319-321, 1955. 

Acetylcarbazole was reportedly converted to the dichlorovinyl derivative 97 using phosphorus pentachloride in refluxing benzene. ... 

An electrochemical method for the synthesis of a series of 4-(alkylamino)-2-phenyloxazolines 139a-f from A -(2,2-dichlorovinyl)amides 135 has been reported. The starting A -(2,2-dichlorovinyl)amide 135, readily available from chloral and amides, undergoes facile reaction with amines to give 136. Cathodic reduction of 136 generates chlorocarbanionic intermediates 137 and 138 that... 

Harada et al. studied the TiO2 photocatalytic mineralization of trimethyl phosphate, trimethyl phosphite, and O, (9-dimethyl ammonium phosphodithioate and reported excellent mass balance based on phosphate, sulfate, and carbon dioxide produced after prolonged illumination [39]. Subsequent studies found the organophosphorus insecticides dimethyl-2,2-dichlorovinyl phosphate [Eq. (5)] and di-methyl-2,2,2-trichloro-I-hydroxyethyl phosphonate were mineralized by solar irradiation in the presence of suspended TiO2 [40] ... 

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