Cresol, hydrogenation

Materials. Horseradish peroxidase (type II, 200 purpurogallin units per mg protein) and non-porous glass beads (75-150 1 diameter) were obtained from Sigma Chemical Co. (St. Louis, MO). p-Cresol, hydrogen peroxide (as a 30% solution in water) and dioxane (HPLC grade) were obtained from Aldrich Chemical Co. (Milwaukee, WI). The actual H2O2 content was determined spectrophotometrically at 240 nm. 

NMR spectrum of 3 methylphenol m cresol) Notice that contrary to what we might expect for a compound with seven peaks for seven different carbons the intensities of these peaks are not nearly the same The two least intense signals those at 8 140 and 8 157 correspond to carbons that lack attached hydrogens... 

A)-Menthol can also be made synthetically by hydrogenation of thymol [89-83-8], which can be produced by isopropylation of y -cresol with propylene (143,144). 

Oxygen evolved from the anodes as well as some hydrogen from the cathodes produces a mist which is trapped by a froth maintained by adding cresyhc acid, sodium siUcate, and gum arabic, or glue plus cresol. Alkaline-earth carbonates prevent lead contamination of the cathode ziac. Most of the lead is deposited ia the cell sludge as iasoluble carbonate—sulfate. 

Other modifications of the polyamines include limited addition of alkylene oxide to yield the corresponding hydroxyalkyl derivatives (225) and cyanoethylation of DETA or TETA, usuaHy by reaction with acrylonitrile [107-13-1/, to give derivatives providing longer pot Hfe and better wetting of glass (226). Also included are ketimines, made by the reaction of EDA with acetone for example. These derivatives can also be hydrogenated, as in the case of the equimolar adducts of DETA and methyl isobutyl ketone [108-10-1] or methyl isoamyl ketone [110-12-3] (221 or used as is to provide moisture cure performance. Mannich bases prepared from a phenol, formaldehyde and a polyamine are also used, such as the hardener prepared from cresol, DETA, and formaldehyde (228). Other modifications of polyamines for use as epoxy hardeners include reaction with aldehydes (229), epoxidized fatty nitriles (230), aromatic monoisocyanates (231), or propylene sulfide [1072-43-1] (232). 

Skin" Notation-. The designation "skin" refers to the potential contribution to the overall exposure by the cutaneous route, including mucous membranes and eyes, either by airborne, or more particularly by direct, contact with the substance. Examples of such substances are phenol (cresol and cumene), hydrogen cyanide, and mercury. The "skin" notation is intended to make known the need to prevent cutaneous absorption so that the TLV is not violated. 

S g of ethyl glycinate hydrochloride were dissolved in 400 cc of ethanol and 33.5 g of salicylic aldehyde were added. It is refluxed for half an hour and cooled. 38 cc of triethylamlne and 25 g of Raney nickel are then added whereafter hydrogenation is carried out at room temperature and under atmospheric pressure. After hydrogen adsorption was complete, the mixture was filtered and the alcohol evaporated off. The residue was taken up with acidified water, extracted with ether to eliminate part of the by-products, consisting mainly of o-cresol, then made alkaline with ammonia and extracted with ethyl acetate. The solvent was removed in vacuo and the residue crystallized from ether/petroleum ether. 36.7 g of o-hydroxybenzyl-aminoacetlc acid ethyl ester melting at 47°C are obtained. 

The kinetics of alkylation by triphenylmethyl compounds have been studied. Hart and Cassis353 found that the alkylation of phenol and o-cresol by triphenylmethyl chloride in o-dichlorobenzene gave non-linear kinetic plots which were, however, rendered linear by presaturation of the reaction mixture with hydrogen chloride, precise third-order kinetics, equation (182)... 

The kinetics of desulphonation of sulphonic acid derivatives of m-cresol, mesitylene, phenol, p-cresol, and p-nitrodiphenylamine by hydrochloric or sulphuric acids in 90 % acetic acid were investigated by Baddeley et a/.701, who reported (without giving any details) that rates were independent of the concentration of sulphuric acid and nature of the catalysing anion, and only proportional to the hydrogen ion concentration. The former observation can only be accounted for if the increased concentration of sulphonic acid anion is compensated by removal of protons from the medium to form the undissociated acid this result implies, therefore, that reaction takes place on the anion and the mechanism was envisaged as rapid protonation of the anion (at ring carbon) followed by a rate-determining reaction with a base. 

Hydrogen bonding between Br2 and 2-substituted phenols having electron-donating group is strong enough to orf/io-brominate these phenols. Therefore, o/t/io-bromination of phenol, o-cresol and 2-allylphenol was promoted by only NBS without amines. 

Two pieces of direct evidence support the manifestly plausible view that these polymerizations are propagated through the action of car-bonium ion centers. Eley and Richards have shown that triphenyl-methyl chloride is a catalyst for the polymerization of vinyl ethers in m-cresol, in which the catalyst ionizes to yield the triphenylcarbonium ion (C6H5)3C+. Secondly, A. G. Evans and Hamann showed that l,l -diphenylethylene develops an absorption band at 4340 A in the presence of boron trifluoride (and adventitious moisture) or of stannic chloride and hydrogen chloride. This band is characteristic of both the triphenylcarbonium ion and the diphenylmethylcarbonium ion. While similar observations on polymerizable monomers are precluded by intervention of polymerization before a sufficient concentration may be reached, similar ions should certainly be expected to form under the same conditions in styrene, and in certain other monomers also. In analogy with free radical polymerizations, the essential chain-propagating step may therefore be assumed to consist in the addition of monomer to a carbonium ion... 

The catalytic lifetime was studied by reusing the aqueous phase for three successive hydrogenation runs of toluene, anisole and cresol. Similar turnover activities were observed during the successive runs. These results show the good stability of the catalytically active iridium suspension as previously described with rhodium nanoparticles. 

The selectivity in the hydrogenation of di-substituted benzenes such as xylene, methylanisole, cresol was also reported. In all cases, the czs-compound is largely the major compound > 80%. The ratio cis/trans decreases with the position of the substituents o > m>p but the identity of the metal does not seem important with this surfactant-stabilized system [45,47]. 

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