Halogenation with concentrated halogen

Chemical Properties and Reactivity. LLDPE is a saturated branched hydrocarbon. The most reactive parts of LLDPE molecules are the tertiary CH bonds in branches and the double bonds at chain ends. Although LLDPE is nonreactive with both inorganic and organic acids, it can form sulfo-compounds in concentrated solutions of H2SO4 (>70%) at elevated temperatures and can also be nitrated with concentrated HNO. LLDPE is also stable in alkaline and salt solutions. At room temperature, LLDPE resins are not soluble in any known solvent (except for those fractions with the highest branching contents) at temperatures above 80—100°C, however, the resins can be dissolved in various aromatic, aUphatic, and halogenated hydrocarbons such as xylenes, tetralin, decalin, and chlorobenzenes. 

Jsomerides of Morphine and Codeine. When morphine is treated with thionyl chloride, phosphorus trichloride or tribromide, the alcoholic hydroxyl group is replaced by the halogen, forming a-chloromorphide and bromomorphide respectively. The former on treatment with concentrated hydrochloric acid is converted into /3-chloromorphide. Schopf and Hirsch have provided evidence that the two are structural isomerides. With the same reagents codeine yields a parallel set of compounds, viz., a- and -chlorocodides, and bromocodide. The chief characteristics of these products may be summarised thus —... 

However, when dissolved in butyl ether and refluxed with concentrated solutions of the halogen acids, dieldrin reacts typically to yield the halohydrin. 

On treatment with concentrated halogen acids, certain hexitols yield 1,6-dideoxy-l,6-dihalo compounds. The structure of the compound so obtained from galactitol, first reported by Bouchardat,404 was later verified by synthesis.405 Allitol is transformed406 into 1,4-anhydro-6-chloro-6-deoxy-DL-allitol and l,4-anhydro-5,6-dichloro-5,6-dideoxy-DL-talitol on treatment with fuming hydrochloric acid at 100°. 

Fujita et al. [18] studied formation of halogenated (chlorinated and brominated) NPEOs and NPECs during wastewater treatment. Halogenated derivatives were found to be produced during the disinfection processes by chlorination accounting for up to 10% of total nonylphenolic compounds. They were found in 25 of 40 WWTPs with concentrations up to 6.5 xgL 1 in secondary effluent and 52.4 jig L-1 in final effluent. Of all halogenated compounds, BrNPECs (nEo = 1-2) were found to be the most abundant. 

The furoxan ring is notably resistant to electrophilic attack and reaction normally takes place at the substituents. Thus aryl groups attached to monocyclic furoxans and the homocyclic ring of benzofuroxans are nitrated and halogenated without disruption of the heterocycle. Reaction with acid is also slow protonation is predicted to occur at N-5 <89KGS1261> and benzofuroxans have pKj, values of ca. 8, similar to those of benzofurazans. Monosubstituted furoxans are, as expected, less stable and can be hydrolyzed to the corresponding carboxylic acid. Treatment of the parent furoxan (3) with concentrated sulfuric acid results in rearrangement to (hydroxyimino)acetonitrile oxide (HON=CHC=N —O ) and subsequent dimerization to bis(hydroxyiminomethyl)furoxan... 

Also, on replacement of oxalato- or carbonato-group by nitro-, chloro-, or bromo-radicles, brown salts are obtained with acid and sodium nitrite, and violet salts on treatment with concentrated hydrochloric or hydro-bromic acid. The brown nitro-compounds are therefore given a formula with the nitro-groups in the 1-, 2-, or eis-position, and the violet halogen salts the formula with halogen in the m-position. The cis-form may be transformed into the /ra -modification by intramolecular rearrangement. Concentrated hydrochloric acid converts carbonato-tctrammino-cobaltie salts first into violo-salts, and on standing, or on rise of temperature, these pass into the prasco- or I-, 6-salts. 

When arsenic trisulphide is exposed to dry hydrogen chloride or hydrogen bromide, it liquefies at the ordinary temperature and on heating complete volatilisation occurs.9 It is not readily attacked by halogen acids. When boiled with concentrated hydrochloric acid it is decomposed, but with great difficulty, and the hydrogen sulphide and arsenious chloride evolved reproduce arsenious sulphide in the receiver.10 A similar reaction occurs when heated with a chloride in the presence of concentrated sulphuric acid, but the decomposition is incomplete.11 The reaction is facilitated by the presence of cuprous chloride or ferric chloride. Only a slight reaction is observed with dilute acid,12 and the... 

A degradation similar to that which results in the formation of 5-hydroxymethylfurfural occurs when hexoses are treated with concentrated halogen acids, but instead of the hydroxymethyl compound, 5-chloromethyl- and 5-bromomethylfurfural (V) are obtained when the corresponding acids are used. Hydrofluoric and hydriodic acids however fail to give the corresponding halogen derivatives. Fenton and Gostling19... 

Over a dozen oxides of the halogens have boon characterized, many of them quite unstable. Perhaps the most important are chlorine dioxide, CJ02, and iodine pentoxide, I2O5. Chlorine dioxide (boiling point 11° C) is an odd molecule (p. 62), but apparently it shows no tendency to dimerize. Although it has been used as an antiseptic in water purification and as a bleach, it must be handled in diluted form for it is explosive when alone. It is formed, along with HCIO4, when chlorates are treated with concentrated sulfuric acid, but a safer preparation involves reduction of a chlorate with oxalic acid. 

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