Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Aromatic hydrocarbons amines

The oxidation potentials 170 ——- 777 of a large number of aromatic hydrocarbons, amines, phenols,heterocycles and olefins are tabulated I0,10a>25-48 65,525-528) an(j nee(j not repeated here. Such potentials have been successfully correlated with HMO-parameters 525 530>538) ie in oxidations with the energy of the highest filled MO (HFMO).Adams 25) and Peover 65) have discussed some precaution to which attention should be paid in such correlations, e.g., shifts in potentials due to the irreversibility of the electrode process or due to fast follow-up reactions. [Pg.141]

Deuterium incorporation in the aromatic hydrocarbon/amine systems is usually considered as involving the radical anion of the aromatic hydrocarbon. CIDNP studies (Gardini and Bargon, 1980) have drawn attention to the fact that trialkylaminium ions undergo fast proton exchange and hence... [Pg.58]

Capillary electrophoresis has been used for the analysis of chiral pollutants, e.g., pesticides, polynuclear-aromatic hydrocarbons, amines, carbonyl compounds, surfactants, dyes, and other toxic compounds. Moreover, CE has also been utilized to separate the structural isomers of various... [Pg.96]

CE has been used for the analysis of chiral pollutants, e.g., pesticides, polynuclear aromatic hydrocarbons, amines, carbonyl compounds, surfactants, dyes, and other toxic compounds. Moreover, CE has also been utilized to separate the structural isomers of various toxic pollutants such as phenols, polyaromatic hydrocarbons, and so on. Sarac, Chankvetadze, and Blaschke " resolved the enantiomers of 2-hydrazino-2-methyl-3-(3,4-dihydroxyphenyl)propanoic acid using CD as the BGE additive. The CDs used were native, neutral, and ionic in nature with phosphate buffer as BGE. Welseloh, Wolf, and Konig investigated the CE method for the separation of biphenyls, using a phosphate buffer as BGE with CD as the chiral additive. Miura et al., used CE for the chiral resolution of seven phenoxy acid herbicides using methylated CDs as the BGE additives. Furthermore, the same group resolved 2-(4-chlorophenoxy) propionic acid (MCPP), 2-(2,4-dichlorophenoxy) propionic acid (DCPP), (2,4-dichlorophenoxy) acetic acid (2,4-D), 2-(4-chlorophenoxy) propionic acid (2,4-CPPA), [(2,4,5-... [Pg.1835]

The underivatized cyclodextrins are rather unusual in their ability to function as water soluble chiral solvating agents. Enantiomeric resolution is observed in the NMR spectra of a wide range of water-soluble cationic and anionic substrates. Organic-soluble cyclodextrins are one of only a few reagents that can be used to enantiomerically resolve the spectra of hydrocarbons such as trisubstituted allenes, a-pinene, and aromatic hydrocarbons. Amines, alcohols, and carboxylic acids can also be resolved with organic-soluble cyclodextrins. [Pg.417]

Metallic sodium. This metal is employed for the drying of ethers and of saturated and aromatic hydrocarbons. The bulk of the water should first be removed from the liquid or solution by a preliminary drying with anhydrous calcium chloride or magnesium sulphate. Sodium is most effective in the form of fine wire, which is forced directly into the liquid by means of a sodium press (see under Ether, Section II,47,i) a large surface is thus presented to the liquid. It cannot be used for any compound with which it reacts or which is affected by alkalis or is easily subject to reduction (due to the hydrogen evolved during the dehydration), viz., alcohols, acids, esters, organic halides, ketones, aldehydes, and some amines. [Pg.143]

Styphnates. Aromatic hydrocarbons (and also some amines and heterocyclic bases) form 1 1-addition products with styphnic acid (2 4 6-trinitroresorcinol),... [Pg.519]

The compound is employed for the characterisation of aromatic hydrocarbons (compare Section IV,9), ethers and amines. [Pg.965]

Typical nonsieve, polar adsorbents are siUca gel and activated alumina. Kquilihrium data have been pubUshed on many systems (11—16,46,47). The order of affinity for various chemical species is saturated hydrocarbons < aromatic hydrocarbons = halogenated hydrocarbons < ethers = esters = ketones < amines = alcohols < carboxylic acids. In general, the selectivities are parallel to those obtained by the use of selective polar solvents in hydrocarbon systems, even the magnitudes are similar. Consequendy, the commercial use of these adsorbents must compete with solvent-extraction techniques. [Pg.292]

PMMA is not affected by most inorganic solutions, mineral oils, animal oils, low concentrations of alcohols paraffins, olefins, amines, alkyl monohahdes and ahphatic hydrocarbons and higher esters, ie, >10 carbon atoms. However, PMMA is attacked by lower esters, eg, ethyl acetate, isopropyl acetate aromatic hydrocarbons, eg, benzene, toluene, xylene phenols, eg, cresol, carboHc acid aryl hahdes, eg, chlorobenzene, bromobenzene ahphatic acids, eg, butyric acid, acetic acid alkyl polyhaHdes, eg, ethylene dichloride, methylene chloride high concentrations of alcohols, eg, methanol, ethanol 2-propanol and high concentrations of alkahes and oxidizing agents. [Pg.262]

In general, peroxomonosulfates have fewer uses in organic chemistry than peroxodisulfates. However, the triple salt is used for oxidizing ketones (qv) to dioxiranes (7) (71,72), which in turn are useful oxidants in organic chemistry. Acetone in water is oxidized by triple salt to dimethyldioxirane, which in turn oxidizes alkenes to epoxides, polycycHc aromatic hydrocarbons to oxides and diones, amines to nitro compounds, sulfides to sulfoxides, phosphines to phosphine oxides, and alkanes to alcohols or carbonyl compounds. [Pg.95]

In general, polycarbonate resins have fair chemical resistance to aqueous solutions of acids or bases, as well as to fats and oils. Chemical attack by amines or ammonium hydroxide occurs, however, and aUphatic and aromatic hydrocarbons promote crazing of stressed molded samples. Eor these reasons, care must be exercised in the choice of solvents for painting and coating operations. Eor sheet appHcations, polycarbonate is commonly coated with a sihcone—sihcate hardcoat which provides abrasion resistance as well as increased solvent resistance. Coated films are also available. [Pg.279]

As with the parent aromatic hydrocarbons, diarylamiaes based oa polycyclic aromatic amines also tead to be more harmful. Thus, /V-phenyl-2-naphthylamine [135-88-6] (PBNA) metaboli2es ia the body to produce small amouats of 2-aaphthylamiae, a known carciaogea (37). ACGIH has desigaated PBNA to be an "iadustrial substance suspect of carciaogenic potential for man."... [Pg.244]

The y -phenylenediamiaes are easily obtained by dinitrating, followed by catalyticaHy hydrogenating, an aromatic hydrocarbon. Thus, the toluenediamiaes are manufactured by nitrating toluene with a mixture of sulfuric acid, nitric acid, and 23% water at 330°C which first produces a mixture (60 40) of the ortho and para mononitrotoluenes. Further nitration produces the 80 20 mixture of 2,4- and 2,6-dinitrotoluene. Catalytic hydrogenation produces the commercial mixture of diamiaes which, when converted to diisocyanates, are widely used ia the production of polyurethanes (see Amines, aromatic, DIAMINOTOLUENES) (22). [Pg.255]

An excess of crotonaldehyde or aUphatic, ahcyhc, and aromatic hydrocarbons and their derivatives is used as a solvent to produce compounds of molecular weights of 1000—5000 (25—28). After removal of unreacted components and solvent, the adduct referred to as polyester is decomposed in acidic media or by pyrolysis (29—36). Proper operation of acidic decomposition can give high yields of pure /n j ,/n7 j -2,4-hexadienoic acid, whereas the pyrolysis gives a mixture of isomers that must be converted to the pure trans,trans form. The thermal decomposition is carried out in the presence of alkaU or amine catalysts. A simultaneous codistillation of the sorbic acid as it forms and the component used as the solvent can simplify the process scheme. The catalyst remains in the reaction batch. Suitable solvents and entraining agents include most inert Hquids that bod at 200—300°C, eg, aUphatic hydrocarbons. When the polyester is spHt thermally at 170—180°C and the sorbic acid is distilled direcdy with the solvent, production and purification can be combined in a single step. The solvent can be reused after removal of the sorbic acid (34). The isomeric mixture can be converted to the thermodynamically more stable trans,trans form in the presence of iodine, alkaU, or sulfuric or hydrochloric acid (37,38). [Pg.283]

MSC undergoes reactions with alcohols, amines, active methylene compounds (in the presence of bases), and aromatic hydrocarbons (in the presence of Friedel-Crafts catalysts) to replace, generally, a hydrogen atom by a methanesulfonyl group (382—401). [Pg.153]

Sodium (metal). Used as a fine wire or as chips, for more completely drying ethers, saturated hydrocarbons and aromatic hydrocarbons which have been partially dried (for example with calcium chloride or magnesium sulfate). Unsuitable for acids, alcohols, alkyl halides, aldehydes, ketones, amines and esters. Reacts violently if water is present and can cause a fire with highly flammable liquids. [Pg.28]

Diglycerol 20-120° Water, alcohols, amines, esters, and aromatic hydrocarbons... [Pg.39]


See other pages where Aromatic hydrocarbons amines is mentioned: [Pg.459]    [Pg.65]    [Pg.590]    [Pg.58]    [Pg.58]    [Pg.459]    [Pg.309]    [Pg.71]    [Pg.45]    [Pg.52]    [Pg.65]    [Pg.74]    [Pg.111]    [Pg.459]    [Pg.84]    [Pg.84]    [Pg.800]    [Pg.297]    [Pg.115]    [Pg.459]    [Pg.65]    [Pg.590]    [Pg.58]    [Pg.58]    [Pg.459]    [Pg.309]    [Pg.71]    [Pg.45]    [Pg.52]    [Pg.65]    [Pg.74]    [Pg.111]    [Pg.459]    [Pg.84]    [Pg.84]    [Pg.800]    [Pg.297]    [Pg.115]    [Pg.128]    [Pg.11]    [Pg.590]    [Pg.70]    [Pg.360]    [Pg.96]    [Pg.108]    [Pg.119]    [Pg.258]    [Pg.262]    [Pg.335]    [Pg.27]   
See also in sourсe #XX -- [ Pg.236 , Pg.240 ]




SEARCH



Aromatic amination

Aromatic amines

Aromatics amination

© 2024 chempedia.info