1,2-Dichloroethane solvent

Synthesis of natural-type aminopolysaccharide having dibenzylchitin structure was achieved by the polymerization of a sugar oxazoline monomer, 1 having one hydroxy group at position 4 (Scheme 4) [9]. The polymerization was carried out with an acid catalyst in 1,2-dichloroethane solvent at reflux temperature. All the H-NMR, C-NMR, and IR spectra as well as elemental analysis data of the isolated polysaccharide supported that the polymerization proceeded by the stereoregular glycosylation to give (1 4)-... 

Polymerization was carried out with 10 mol% catalyst at in 1,2-dichloroethane solvent at reflux. Determined by GPC. 

The major disadvantage of the HSAB principle is its qualitative nature. Several models of acid-base reactions have been developed on a quantitative basis and have application to solvent extraction. Once such model uses donor numbers [8], which were proposed to correlate the effect of an adduct on an acidic solute with the basicity of the adduct (i.e., its ability to donate an electron pair to the acidic solute). The reference scale of donor numbers of the adduct bases is based on the enthalpy of reaction. A//, of the donor (designated as B) with SbCb when they are dissolved in 1,2-dichloroethane solvent. The donor numbers, designated DN, are a measure of the strength of the B—SbCb bond. It is further assumed that the order of DN values for the SbCb interaction remains constant for the interaction of the donor bases with all other solute acids. Thus, for any donor base B and any acceptor acid A, the enthalpy of reaction to form B A is ... 

Sachleben, R.A., Bonnesen, P.V., Desazeaud, T. et al. 1999. Surveying the extraction of cesium nitrate by 1,3-altemate calix[4]arene crown-6 ethers in 1,2-dichloroethane. Solvent Extr. Ion Exch. 17 (6) 1445-1459. 

Scheme 12.6 Pro-catalyst-dependent regioselectivity in the Pd-catalysed cyclo-isomerisation of 1,6-dienes DCE = 1,2-dichloroethane (solvent) see the text for catalysts.

Sachleben, R. A., Bonnesen, P. V., Descazeaud, T., Haverlock, T. J., Urvoas, A., and Moyer, B. A. Surveying the Extraction of Cesium Nitrate by 1,3-Altemate Calix[4]arene Crown-6 Ethers in 1,2-Dichloroethane, Solvent Extr. Ion Exch. 17 (1999), 1445-1459. 

The reaction temperature had a dramatic impact on the enantioselectivity of the silane addition. Using acetophenone, diphenylsilane and the (S-Binap)Rh(PPh3)2 catalyst as a model system, the initial reaction temperature was varied from -40°C to 55°C. When carried out under the standard conditions (vide supra), the reduction gave an optical yield of 26% (5-isomer). Lowering the initial temperature to 0°C caused a decrease in the e.e. to 12% and decreasing the temperature further still to -40°C resulted in an optical yield of only 7%. Increasing the initial temperature, on the other hand, to 55°C (1,2-dichloroethane solvent) raised the optical yield to 55%. 

Since 4,7-dihydro-l,3-dioxepin (IA) is both the simplest and one of the more easily prepared 1,3-dioxepin monomers (Table I), copolymerization of equimolar mixtures of IA-MA were first examined under a variety of conditions (Table II). As shown, yields of 1 1 alternating IA-MA copolymer are highly dependent upon polymerization conditions, with highest conversions obtained in 1,2-dichloroethane solvent. Also, incremental or controlled addition of initiator improves yields of copolymer. Using DCE solvent, the copolymers precipitated during polymerization. Copolymerization without added initiator was not observed. 

Exclusion of Free Acid Impurities as the Initiating Species First, the NMR spectrum of trifluoromethanesulfonic acid in the 1,2-dichloroethane solvent used gave a singlet at 69.03, owever the spectrum of 1,1,2-tricyanoviny1-2-trifluoromethane-sulfonate 1 in the same solvent shows no peak downfield after 3 hours which indicates that the hydrolysis of the initiator to trifluoromethanesulfonic acid is not occurring during the polymer initiation step. 

Place 0.375 g ytterbium (III) trifluoromethanesulfonate hydrate catalyst (ytterbium triflate) into a 25-mL round-bottom flask. Add 10 mL of 1,2-dichloroethane solvent followed by 0.400 mL of concentrated nitric acid (automatic pipette). Add two boiling stones to the flask. To fhis solution, weigh out and add approximately 6 millimoles of the aromatic substrate. Connect the round-bottom flask to a reflux condenser and clamp it into place on a ring stand. Use a very slow flow of water through the condenser. With a hot plate, heat the mixture to reflux for 1 hour. 

Figure 13 Time course of the formation of polystyryl cation and monomer conversion. Polymerization conditions 10°C 1,2-dichloroethane solvent [CF3S03H]o = 2.4mmol [styrene]o = 0.391 molM. ...

Polymerizations carried out with boron trifluoride catalyst in dichloroethane solvent result in several reactions that occur simultaneously. A polymer and a copolymer with a different cyclic... 

Distribution by weight of blister chemicals located at the four depots earlier mentioned is as follows Corny, in high-tonnage containers 293 tonnes of Lewisite, 807 tonnes of Mustard, and 157/71 tonnes of Mustard -Lewisite mixtures (the denominator shows the number of tonnes of Mustard -Lewisite mixture in dichloroethane solvent) Kambarka, in high-tonnage containers 6349 tonnes of Lewisite Khizner, in artillery munitions 129 tonnes of Lewisite Maradykovsky, in aerial bombs 149 tonnes of Mustard -Lewisite mixtures. 

Now calculate the molecular weight of the substance precisely as described on p. 442. The weight of the solvent employed may be calculated from the following densities methanol, 0 810 rectified spirit, 0-807 acetone, 0 797 ethyl acetate, 0 905 chloroform, 1 504 carbon tetrachloride, 1 582 benzene, 0 880 toluene, 0-871 cyclohexane, 0-724 i, 2-dichloroethane, 1 252. 

A hydroxyl group is a very powerful activating substituent and electrophilic aro matic substitution m phenols occurs far faster and under milder conditions than m ben zene The hrst entry m Table 24 4 for example shows the monobrommation of phenol m high yield at low temperature and m the absence of any catalyst In this case the reac tion was carried out m the nonpolar solvent 1 2 dichloroethane In polar solvents such as water it is difficult to limit the brommation of phenols to monosubstitution In the fol lowing example all three positions that are ortho or para to the hydroxyl undergo rapid substitution... 

Air. Biofilters are an effective way of dealing with air from industrial processes that use halogenated solvents such chloromethane, dichioromethane, chloroethane, 1,2-dichloroethane and vinyl chloride, that support aerobic growth (26). Both compost-based dry systems and trickling filter wet systems are in use. Similar filters could be incorporated into pump-and-treat operations. 

Solvents used for dewaxing are naphtha, propane, sulfur dioxide, acetone—benzene, trichloroethylene, ethylenedichloride—benzene (Barisol), methyl ethyl ketone—benzene (benzol), methyl -butyl ketone, and methyl / -propyl ketone. Other solvents in commercial use for dewaxing include /V-methylpyrrolidinone, MEK—MIBK (methyl isobutyl ketone), dichloroethane—methylene dichloride, and propfyene—acetone. 

Both the carboxyl and the mercapto moieties of thioglycolic acid are acidic. Dissociation constants at 25°C are for pR, 3.6 pi, 10.5. ThioglycoHc acid is miscible ia water, ether, chloroform, dichloroethane and esters. It is weakly soluble ia aHphatic hydrocarbons such as heptane, hexane. Solvents such as alcohols and ketones can also react with thioglycolic acid. 

Chlorination of various hydrocarbon feedstocks produces many usehil chlorinated solvents, intermediates, and chemical products. The chlorinated derivatives provide a primary method of upgrading the value of industrial chlorine. The principal chlorinated hydrocarbons produced industrially include chloromethane (methyl chloride), dichloromethane (methylene chloride), trichloromethane (chloroform), tetrachloromethane (carbon tetrachloride), chloroethene (vinyl chloride monomer, VCM), 1,1-dichloroethene (vinylidene chloride), 1,1,2-trichloroethene (trichloroethylene), 1,1,2,2-tetrachloroethene (perchloroethylene), mono- and dichloroben2enes, 1,1,1-trichloroethane (methyl chloroform), 1,1,2-trichloroethane, and 1,2-dichloroethane (ethylene dichloride [540-59-0], EDC). 

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