Chlorinated alkyl carbonate

Tackifiers. Phenolic resins are added to increase strength, oils resistance and resiliency of NBR adhesives. On the other hand, tack and adhesive properties can be improved by adding chlorinated alkyl carbonates. To impart tack, hydrogenated rosin resins and coumarone-indene resins can be added. 

This includes bioremediation cases of contaminated sites with several toxic and carcinogenic pollutants, such as petroleum hydrocarbons, PAHs, dichlorobenzene, chlorinated hydrocarbons, carbon tetrachloride, Dicamba, methyl bromide, trinitrotoluene, silicon-based organic compounds, dioxins, alkyl-phenol polyethoxylates, nonylphenol ethoxylates, and polychlorinated biphenyls. The following is a brief summary of each case. 

If a dichloroacetic acid salt is used as the alkyl halide to add to the lithioarsole (41), the arsole (45) is formed. This loses the elements of chlorine and carbon dioxide on heating, giving an intermediate carbene which gives ring expansion to the arsenin (46 equation 9) (74TL303). 

Cretcher and Pittenger,8 7 and also Fair bourne and co-workers i i have described the addition of various alkoxide ions to epichluru-hydrin. The reaction in rather alow, but product are formed as anticipated by attack on the terminal epoxide carbon (Eq. 567). The came products have been reported by several authors 13-M1 to form likewise under acid condition. Apparently the dectrr.-ncgatmty of the chlorine atom overcomes the normal tendency for attack at the most highly alkylated carbon atom under addfr dm... 

On the other hand, bisalkylation of diethyl 1 -chloro-1 -lithioalkanephosphonates can also be achieved by copper(I)-catalysed replacement of chlorine by carbon-nucleophiles with subsequent alkylation of the resulting lithiocarbanion 38> (Eq. (34)). 

Furthermore, di- and polychlorination are much less prevalent. Dicarboxylic acids are predominantly chlorinated in the middle of the chain, and adamantane and bicyclo[2.2.2]octane at the bridgeheads by this procedure. The reasons for the high co - 1 specificity are not clearly understood. Alkyl bromides can be regioselectively chlorinated one carbon away from the bromine (to give vic-bromochlorides) by treatment with PCls. Alkyl chlorides can be converted to vic-dichlorides by treatment with Mods. " Enhanced selectivity at a terminal position of w-alkanes has been achieved by absorbing the substrate onto a pentasil zeolite. In another regioselective chlorination, alkanesulfonamides... 

In order to improve transport through biological barriers of the plants, we thought that the chemical modification of known pesticides with 1-chloroalkyl alkyl carbonates containing sugar or glycerol moiety should be of some interest. For this purpose we synthesized at laboratory scale several new a-chlorinated carbonates (Ref. 77). The products prepared and results obtained are depicted on scheme 66. 

Thus, research efforts in different industrial laboratories have been directed toward the preparation of 1-bro-moalkyl alkyl carbonates assumed to be more stable than the 1-iodo derivatives, and more reactive than the parent chloro compounds. For example, 1-bromoethyl ethyl carbonate was made by the halide exchange of 1-chloroethyl ethyl carbonate with LiBr or NaBr, or by a radical type bro-mination of diethyl carbonate (Ref. 82). However, in the case of halide exchange, the conversion is low and a mixture results. Even with a large excess of bromide salt, this problem remains. Radical bromination was found to give unsatisfactory results for the same reasons than the chlorination, and failed in the case of unsymmetrical dialkyl carbonates because of its non-regioselectivity. 

T eveloping the resistance of certain insect species to chlorinated hydro-carbon insecticides led to the recent discovery of the IV-alkyl and 2V,2V-dialkyl carbamate esters as useful broad spectrum insecticides. The best known insecticide of this class is Sevin (l-naphthyl-N-methylcarba-mate) which is one of the most used insecticides. In Egypt Sevin has been extensively used to control cotton pests—e.g., pink boll worm, boll weevil, and the cotton leaf worm—and also to control several other... 

With simple alkyl groups attached to the a-carbon of the carboxylic acid (the acids in Table 9.11) the pKa s are all about the same (as measured in aqueous ethanol). However, as seen with the chloroethanoic (chloroacetic) acids (Table 9.11), the effect of electron-withdrawing groups is to increase the acidity (decrease the pKa) of the carboxylic acid. As expected, a correlation can also be effected with the corresponding downfield shifts of the chlorine bearing carbon atom in the respective NMR spectra of the chloroethanoic (chloroacetic) acids. 

The action of sodium alkyl carbonates on 3-chloro-l,2-benzisothiazole 1,1-dioxide (64) produces mixtures of AT-alkoxycarbonylsaccharins (65) and pseudosaccharin anhydride (66), together with dialkyl pyrocarbonates. The product ratio of (65) to (66) decreases in the order (R = ) Me > Et > Pr > Bu. The initial step in the reaction is considered to be a nucleophilic displacement of chlorine by ROCOO ion. ... 

Chlorination of methane and halogenation of alkanes generally proceed by way of free radical intermediates Alkyl radicals are neutral and have an unpaired electron on carbon... 

Because carbon is sp hybridized m chlorobenzene it is more electronegative than the sp hybridized carbon of chlorocyclohexane Consequently the withdrawal of electron density away from carbon by chlorine is less pronounced m aryl halides than m alkyl halides and the molecular dipole moment is smaller... 

Carbon Cha.in Backbone Polymers. These polymers may be represented by (4) and considered derivatives of polyethylene, where n is the degree of polymeriza tion and R is (an alkyl group or) a functional group hydrogen (polyethylene), methyl (polypropylene), carboxyl (poly(acryhc acid)), chlorine (poly(vinyl chloride)), phenyl (polystyrene) hydroxyl (poly(vinyl alcohol)), ester (poly(vinyl acetate)), nitrile (polyacrylonitrile), vinyl (polybutadiene), etc. The functional groups and the molecular weight of the polymers, control thek properties which vary in hydrophobicity, solubiUty characteristics, glass-transition temperature, and crystallinity. 

Aluminum chloride dissolves readily in chlorinated solvents such as chloroform, methylene chloride, and carbon tetrachloride. In polar aprotic solvents, such as acetonitrile, ethyl ether, anisole, nitromethane, and nitrobenzene, it dissolves forming a complex with the solvent. The catalytic activity of aluminum chloride is moderated by these complexes. Anhydrous aluminum chloride reacts vigorously with most protic solvents, such as water and alcohols. The ability to catalyze alkylation reactions is lost by complexing aluminum chloride with these protic solvents. However, small amounts of these "procatalysts" can promote the formation of catalyticaHy active aluminum chloride complexes. 

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