Phenol trialkylated

The above is a general procedure for preparing trialkyl orthophosphates. Similar yields are obtained for trimethyl phosphate, b.p. 62°/5 mm. triethyl phosphate, b.p. 75-5°/5 mm. tri-n-propyl phosphate, b.p. 107-5°/5 mm. tri-Mo-propyl phosphate, b.p. 83-5°/5 mm. tri-wo-butyl phosphate, b.p. 117°/5-5 mm. and tri- -amyl phosphate, b.p. 167-5°/5 mm. The alkyl phosphates are excellent alkylating agents for primary aromatic amines (see Section IV,41) they can also be ua for alkylating phenols (compare Sections IV,104-105). Trimethyl phosphate also finds application as a methylating agent for aliphatie alcohols (compare Section 111,58). 

Substitution reactions of B-trich1oro- X-trialkyl (or triaryl)bora2iQes and alchohols, phenols, or excess amine yield the corresponding bora2iaes (100,94). 

Sulfonic esters are most frequently prepared by treatment of the corresponding halides with alcohols in the presence of a base. The method is much used for the conversion of alcohols to tosylates, brosylates, and similar sulfonic esters. Both R and R may be alkyl or aryl. The base is often pyridine, which functions as a nucleophilic catalyst, as in the similar alcoholysis of carboxylic acyl halides (10-21). Primary alcohols react the most rapidly, and it is often possible to sulfonate selectively a primary OH group in a molecule that also contains secondary or tertiary OH groups. The reaction with sulfonamides has been much less frequently used and is limited to N,N-disubstituted sulfonamides that is, R" may not be hydrogen. However, within these limits it is a useful reaction. The nucleophile in this case is actually R 0 . However, R" may be hydrogen (as well as alkyl) if the nucleophile is a phenol, so that the product is RS020Ar. Acidic catalysts are used in this case. Sulfonic acids have been converted directly to sulfonates by treatment with triethyl or trimethyl orthoformate HC(OR)3, without catalyst or solvent and with a trialkyl phosphite P(OR)3. ... 

The formation and reaction of peroxyl radicals derived by reaction of tervalent phosphorus compounds with oxygen have attracted interest. Photolysis of trialkyl phosphites in oxygenated solutions of aromatic hydrocarbons gives phenols. " Phosphorus trichloride reacts with 1,2-dichloroethylene, in the presence of oxygen, to give (17). It is tempting to suggest that both reactions occur via similar intermediates, e.g. (15) and (16). 

Organophosphate Ester Hydraulic Fluids. Organophosphate esters are made by condensing an alcohol (aryl or alkyl) with phosphorus oxychloride in the presence of a metal catalyst (Muir 1984) to produce trialkyl, tri(alkyl/aryl), or triaryl phosphates. For the aryl phosphates, phenol or mixtures of alkylated phenols (e.g., isobutylated phenol, a mixture of several /-butylphenols) are used as the starting alcohols to produce potentially very complex mixtures of organophosphate esters. Some phosphate esters (e.g., tricresyl and trixylyl phosphates) are made from phenolic mixtures such as cresylic acid, which is a complex mixture of many phenolic compounds. The composition of these phenols varies with the source of the cresylic acid, as does the resultant phosphate ester. The phosphate esters manufactured from alkylated phenylated phenols are expected to have less batch-to-batch variations than the cresylic acid derived phosphate esters. The differences in physical properties between different manufacturers of the same phosphate ester are expected to be larger than batch-to-batch variations within one manufacturer. 

Of these reactions, the reaction of the peroxyl radical with phosphite is the slowest. The rate constant of this reaction ranges from 102 to 103 L mol 1 s 1 which is two to three orders of magnitude lower than the rate constant of similar reactions with phenols and aromatic amines. Namely, this reaction limits chain propagation in the oxidation of phosphites. Therefore, the chain oxidation of trialkyl phosphites involves chain propagation reactions with the participation of both peroxyl and phosphoranylperoxyl radicals ... 

It is now known1 that trialkyl phosphates will indeed alkylate phenols. The idea has been extended2 to the production of methyl ethers from alcohols and trimethyl phosphate, and of a butyl ether according to the equation... 

The catalysed two-phase adaptation of the Atherton-Todd procedure is effective for the phosphorylation of primary alcohols and of phenols [6] to produce trialkyl phosphates and dialkyl aryl phosphates. Trialkyl phosphates have also be obtained in high yield (>75%) from the alkylation of preformed tctra-n-butylammonium di-/-butylphosphate [7], Subsequent cleavage of the /-butyl groups provide a simple synthesis of monoalkyl phosphates. 

Uberwiegend in 4-Stellung werden Phenole durch l,3,5-Trialkyl-hexahydro-l,3,5-triazine als Mannich-Reagenzien aminomethyliert1. 

Although not studied in detail, the mechanism of phenol alkylation with methanol can be formulated on similar grounds by assuming that the initial interaction of phenol and methanol with MgO gives surface phenoxide and methoxide ions and OH groups [these species are known to be formed separately on MgO (263)]. This initial reaction is then followed by elimination of H20 and formation of trialkyl phenol. 

The data in Figure 2 for trialkylated phenol products are similar to those in Figure 1, with two important differences. The abrupt change in effectiveness of the trialkylated phenols occurs when R is Ci0H2i to C12H25. Although in the more severe tests these compounds are about as effective as the 2,6-dialkyl-p-cresols, in the least severe test they are considerably less effective. It is evident that 2,4,6-trioctadecylphenol is also a very potent antioxidant. 

All four types of phenols alkylated by a-olefins are effective antioxidants. However, the alkylated p-cresols are the most effective, followed closely by the 2,4,6-trialkylated phenols. The alkylated xylenols have a lower degree of effectiveness in polypropylene. Of the entire series, 2,6-dioctadecyl-p-cresol has the best over-all properties. It is one of the most effective non-discoloring antioxidants now known for polypropylene. It is especially useful under adverse conditions, such as high temperatures, or in thin films. 

A somewhat different effect is shown in Figure 4 by the data from the tests using 6J mil bars. The curves shown are for the 160 °C. test, but those for the 140 °C. test have similar shapes. A definite maximum in effectiveness is observed for both types. Again, a somewhat higher molecular weight is needed for the trialkylated phenols than for the dialkylated p-cresols. 

Two differences were observed between the dialkylated p-cresols and the trialkylated phenols. First, the sharp increase in activity always occurs at a somewhat higher molecular weight for the trialkylated phenols secondly, the p-cresol products are generally somewhat more effective throughout the entire range of molecular weights. The first may be... 

Trifluoromethylated phenols and anilines have been made by reaction of ortho- and pani-quinoncs with trialkyl(trifluoromethyl)silanes, under base catalysis with subsequent reduction or reductive amination of the reaction products. 

Preparation.- Trialkyl or triaryl phosphites and trithiophosphites (55) can be obtained in 50-90% yields from white phosphorus, carbon tetrachloride, triethylamine, and the appropriate alcohol, phenol, or thiol in a polar aprotic solvent such as dimethylformamide. A series of racemic phenylbis(dialkylamino)phosphines (56) have been prepared in a one-pot synthesis as shown the bulk of the dicyclohexyl-amino group prevents substitution of the second chlorine atom, and the products (56) are claimed to be stable to air and moisture. In a one-pot synthesis tris(diethylamino)-phosphine has been treated successively with three different alcohols to give a 89% yield of the thiophosphate (57) after oxidation with sulphur. ... 

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