Preparations insecticides

It is also necessary, from the military point of view, that the insecticides supplied to troops in the field be readily convertible into end-use items. It should not be necessary to go through an involved procedure in preparing insecticides for field utilization. For example, the earliest lots of DDT that were received in the North African theater were of the consistency of beeswax, and were extremely difficult to get into solution. It was necessary to process all this material through meat grinders, of the hamburg variety, requisitioned from the civilian economy before this material could be satisfactorily dissolved in Diesel oil. Such a situation complicates field operations unnecessarily, and should be avoided in the development of future insecticides. 

Uses Lead scavenger was used in anti knock (leaded) gasoline grain and fruit fumigant waterproofing preparations insecticide medicines general solvent organic synthesis. 

Unsaturated 5(4//)-oxazolones have also been used as intermediates to prepare analogues with diverse biological activities. For example, the oxazolone derived from 4-biphenylcarboxaldehyde is a synthetic precursor of the antiinflammatory agent 4-biphenylacetic acid." In addition, 2-substituted oxazolones derived from 2-thioarylbenzaldehydes are starting materials for the preparation of dibenzothie-pine derivatives that are useful to treat schizophrenia." Other oxazolones have been used as intermediates to prepare insecticides and acaricides." ... 

The control of scale insects, whiteflies, plant hoppers, aphids, chinch bugs, phytophagous beetles, flies, caterpillars, masquitoes, and stored product pests costs more than one-half billion dollars annually in the United States alone. In the last decade great progress was made in the commercial production of microbial insecticides which can partially replace synthetically prepared insecticides. 

The concept of bioisosterism has been used to theoretically evaluate structural variation Organophosphorous Agrochemicals within the lead structures of synthetic or natural origin prior to and during the preparation Insecticides (Tables 17.3a,b). Oiganophorous of molecules of specified efficacy, safety, sta- insecticides bind to Acetylcholinesterase (AchE),... 

Intermediate in chemical synthesis coolant lubricant heat-transfer medium polyester dyeing termite-control preparations insecticides... 

The report by Haas and Guardia (18) pertains to their efforts to apply immunological methods for the assay of pesticide residues, and expresses their aim to test the suitability of methods for field analytical purposes. Haas and Guardia also used DDT and malathion to represent two of the most important classes of insecticides, chlorinated hydrocarbons and organophosphorus compounds. They first attempted to prepare insecticide-protein antigens in which enzymes were used as the protein carrier. Antiserum of rabbits injected with DDA-carbonic anhydrase or malathion-chymotrypsin failed to show the presence of the respective antibodies. 

Draw the electron-dot formula for PCI3, phosphorus trichloride, used commercially to prepare insecticides and flame retardants. 

HOCH2CH = CHCH2OH. Colourless stable liquid used in the manufacture of insecticides, resins and pharmaceuticals. Both cis- and rruwi-isomers are known. Prepared by hydrogenation of butynediol over a catalyst. 

CaSO4-0-5HiO, prepared by heating gypsum at 130 "C, is used as plaster of Paris. Gypsum and anhydrite are used for H2SO4 production and gypsum is used as a soil additive and as an inert additive to pharmaceuticals and insecticides. 

M.p. I08-5 C. Ordinary DDT contains about 15% of the 2,4 -isomer, and is prepared from chloral, chlorobenzene and sulphuric acid. It is non-phytotoxic to most plants. It is a powerful and persistent insecticide, used most effectively to control mosquitoes in countries where malaria is a problem. It is stored in the bodies of animals and birds. 

Basic copper ethanoate arsenates(iii) prepared from verdigris (or other basic copper salt), sodium arsenate(m) and ethanoic acid. Used in insecticides for spraying fruit trees. Readily decomposed to soluble arsenic compounds so use is very restricted. 

A contact insecticide with the trade name Sevin . White solid, m.p. 142 C. It is prepared by reaction of I-naphthol with methyl isocyanate or with phosgene and a base. 

Trichlorothiazole, which behaves as an insecticide, can be prepared by the reaction at 150 to 200°C of sulfur with either 1.2.2.2-tetrachlorethylisocyanide dichloride (103), JV-(l,2,2,2-tetrachlor-ethyl)formimidine (104), or by the reaction of sulfur chlorides at... 

Tetrahydrofurfuryl alcohol is a solvent and coupling agent for a phosphate-type insecticide used to control the gypsy moth. Esters of tetrahydrofurfuryl alcohol are used in preparations employed as insect repeUents. Tetrahydrofurfuryl alcohol is also used as a solvent—carrier for an EPA-approved paper sHmicide formulation. In this appHcation, the exceptional solvent action of tetrahydrofurfuryl alcohol prevents separation of the... 

Cyclodienes. These are polychlorinated cycHc hydrocarbons with endomethylene-bridged stmctures, prepared by the Diels-Alder diene reaction. The development of these insecticides resulted from the discovery in 1945 of chlordane, the chlorinated adduct of hexachlorocyclopentadiene and cyclopentadiene (qv). The addition of two Cl atoms across the double bond of the ftve-membered ring forms the two isomers of chlordane [12789-03-6] or l,2,4,5,6,7,8,8-octachloro-2,3,3t ,4,7,7t -hexahydro-4,7-methano-lJT-indene, QL-trans (mp 106.5°C) and pt-tis (32) (mp 104.5°C). The p-isomerhas signiftcantiy greater insecticidal activity. Technical chlordane is an amber Hquid (bp 175°C/267 Pa, vp 1.3 mPa at 25°C) which is soluble in water to about 9 fig/L. It has rat LD qS of 335, 430 (oral) and 840, 690 (dermal) mg/kg. Technical chlordane contains about 60% of the isomers and 10—20% of heptachlor. It has been used extensively as a soil insecticide for termite control and as a household insecticide. 

Chlorinated Terpenes. A group of incompletely characterized insecticidal compounds has been produced by the chlorination of the naturally occurring terpenes. Toxaphene [8001-35-2] is prepared by the chlorination of the bicycHc terpene, camphene [79-92-5] to contain 67—69% chlorine and has the empirical formula C QH QClg. The technical product is a yellowish, semicrystalline gum (mp 65—90°C, d 1.64) and is a mixture of 175 polychloro... 

The successful employment of any insecticide depends on its proper formulation into a preparation that can be appHed for insect control with safety to the apphcator, animals, and plants. Insecticides are commonly formulated as dusts, water dispersions, emulsions, and solutions. The preparation and use of such formulations involves accessory agents such as dust carriers, solvents, emulsifiers, wetting and dispersing agents, stickers, and deodorants or masking agents (1). 

Encapsulated fonofos, a soil insecticide, was developed to coat seeds before they were planted (72). Encapsulation reduces oral toxicity 100-fold and dermal toxicity 10-fold while extending activity of the fonofos. Other encapsulated pesticides available include permethrin and parathion (69). Significantly, all commercial encapsulated pesticides are prepared by interfacial polymeri2ation. 

Naphthol is mainly used in the manufacture of the insecticide carbaryl (59), l-naphthyl A/-methyicarbamate/ iJ-2j5 - (Sevin) (22), which is produced by the reaction of 1-naphthol with methyl isocyanate. Methyl isocyanate is usually prepared by treating methylamine with phosgene. Methyl isocyanate is a very toxic Hquid, boiling at 38°C, and should not be stored for long periods of time (Bhopal accident, India). India has developed a process for the preparation of aryl esters of A/-alkyl carbamic acids. Thus l-naphthyl methylcarbamate is prepared by refluxing 1-naphthol with ethyl methylcarbamate and POCl in toluene (60). In 1992, carbaryl production totaled > 11.4 x 10 t(35). Rhc ne-Poulenc, at its Institute, W. Va., facihty is the only carbaryl producer in United States. 

AIkyl-Ai,A/-diaLkyl-l-naphthalenecarboxamides are useful herbicides (86) and the 2,2-dimeth5lhydra2ide of 1-naphthalenecarboxyhc acid has been patented as a plant growth regulator (87). 2-Propynyl-2-naphthalenecarboxylate [53548-27-9] and similar esters are insecticides (88). 1-Naphthaleneacetic acid, the plant growth regulator, has been prepared from naphthalene, concentrated HCl, and paraformaldehyde without isolation of intermediate 1-chloromethylnaphthalene or l-naphthaleneacetonitnle (89). 

CitroneUal can also be converted to the ds- [92471-23-3] (88) and / 3 -/)-menthane-3,8-diol [91739-72-9] (89) by reaction with dilute acids (176,177). The glycol mixture can be readily purified by distillation and the two isomers easily separated. The glycols are usehil as insect repellents (qv) and are especially effective against mosquitos (178). Derivatives of the glycols have been prepared and are usehil as insecticides and plant growth regulators (179). 

Uses. /-Butyl hypochlorite has been found useful in upgrading vegetable oils (273) and in the preparation of a-substituted acryflc acid esters (274) and esters of isoprene halohydrins (275). Numerous patents describe its use in cross-linking of polymers (qv) (276), in surface treatment of mbber (qv) (277), and in odor control of polymer latexes (278). It is used in the preparation of propylene oxide (qv) in high yield with Httle or no by-products (269,279). Fluoroalkyl hypochlorites are useful as insecticides, initiators for polymerizations, and bleaching and chlorinating agents (280). 

MisceUaneous uses include extraction and purification of penicillin, alkaloids, vitamins, and flavors, and as an intermediate in the preparation of dyes and pesticides. Chloroform has also been used as a fumigant and insecticide, in the formulation of cough symps, toothpastes, liniments, and toothache preparations. These latter uses were banned by the FDA in 1976 (38). 

Halogenation. Halogens and halogen acids add readily to the unsaturated carbon linkages of the cyclopentadiene molecule. By such additions a series of halogenated derivatives range, in the case of the chloride, from 3-chlotocydopentene to tetrachlorocyclopentane. Of all the possible chloto derivatives of CPD, only hexachlorocyclopentadiene [77-47-4] ever reached commercial status. It was used as an insecticide, but this use has been discontinued because of its toxicity (see Chlorocarbons and chlorohydrocarbons, toxic aromatics). It can be prepared by a Hquid phase chlorination of CPD below 50°C (29). 

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