Phosphoric acid alkyl phosphates

For extraction of uranium from sulfate leach Hquors, alkyl phosphoric acids, alkyl phosphates, and secondary and tertiary alkyl amines are used in an inert diluent such as kerosene. The formation of a third phase is suppressed by addition of modifiers such as long-chain alcohols or neutral phosphate esters. Such compounds also increase the solubihty of the amine salt in the diluent and improve phase separation. 

In a similar way, the phosphorus atom gives rise to the surface-active esters of phosphoric acid (alkyl phosphates) and the alkyl phosphonates, in which the phosphorus atom is directly bonded to a carbon atom. 

Polyphosphoric acid supported on diatomaceous earth (p. 342) is a petrochemicals catalyst for the polymerization, alkylation, dehydrogenation, and low-temperature isomerization of hydrocarbons. Phosphoric acid is also used in the production of activated carbon (p. 274). In addition to its massive use in the fertilizer industry (p. 524) free phosphoric acid can be used as a stabilizer for clay soils small additions of H3PO4 under moist conditions gradually leach out A1 and Fe from the clay and these form polymeric phosphates which bind the clay particles together. An allied though more refined use is in the setting of dental cements. 

Acid ester phosphates with an alkyl chain up to C6 have little solubility whereas neutralized esters are soluble in water. In ethanol and isopropanol most of phosphoric acid esters and their salts are soluble. If the products are based on ethoxylated alcohols their solubility in water will increase as the degree of ethoxylation increases. The solubility in organic solvents like gasoline, benzene, perchlorethylene, and other apolar liquids recedes with an increase in the degree of ethoxylation but are increased by a higher alkyl chain. 

In addition to their poor solubility in water, alkyl phosphate esters and dialkyl phosphate esters are further characterized by sensitivity to water hardness [37]. A review of the preparation, properties, and uses of surface-active anionic phosphate esters prepared by the reactions of alcohols or ethoxylates with tetra-phosphoric acid or P4O10 is given in Ref. 3. The surfactant properties of alkyl phosphates have been investigated [18,186-188]. The critical micelle concentration (CMC) of the monoalkyl ester salts is only moderate see Table 6 ... 

For converting rust to clinging layers as a basis for coatings of paint and varnish, the addition of alkyl phosphates to phosphoric acid is suggested to improve its wettability and penetration [260]. 

The development of monoalkyl phosphate as a low skin irritating anionic surfactant is accented in a review with 30 references on monoalkyl phosphate salts, including surface-active properties, cutaneous effects, and applications to paste and liquid-type skin cleansers, and also phosphorylation reactions from the viewpoint of industrial production [26]. Amine salts of acrylate ester polymers, which are physiologically acceptable and useful as surfactants, are prepared by transesterification of alkyl acrylate polymers with 4-morpholinethanol or the alkanolamines and fatty alcohols or alkoxylated alkylphenols, and neutralizing with carboxylic or phosphoric acid. The polymer salt was used as an emulsifying agent for oils and waxes [70]. Preparation of pharmaceutical liposomes with surfactants derived from phosphoric acid is described in [279]. Lipid bilayer vesicles comprise an anionic or zwitterionic surfactant which when dispersed in H20 at a temperature above the phase transition temperature is in a micellar phase and a second lipid which is a single-chain fatty acid, fatty acid ester, or fatty alcohol which is in an emulsion phase, and cholesterol or a derivative. 

An electric conductive rubber base containing carbon black is laminated with an electric conductive cover layer of phosphoric acid ester plasticizer and other ionic surfactants to prepare antistatic mats, where the covers have colors other than black. It is also reported that alkyl acid phosphates act as color stabilizer for rubber. Small amounts of phosphate esters are helpful in restoring reclaimed rubber to a workable viscosity [284,290]. Esters of phosphoric acid are used in the production of UV-stable and flame-retarded alkylbenzenesulfonate copolymer compositions containing aliphatic resins and showing a high-impact strength... 

A mixture of monolauryl phosphate sodium salt and triethylamine in H20 was treated with glycidol at 80°C for 8 h to give 98% lauryl 2,3-dihydro-xypropyl phosphate sodium salt [304]. Dyeing aids for polyester fibers exist of triethanolamine salts of ethoxylated phenol-styrene adduct phosphate esters [294], Fatty ethanolamide phosphate surfactant are obtained from the reaction of fatty alcohols and fatty ethanolamides with phosphorus pentoxide and neutralization of the product [295]. A double bond in the alkyl group of phosphoric acid esters alter the properties of the molecule. Diethylethanolamine salt of oleyl phosphate is effectively used as a dispersant for antimony oxide in a mixture of xylene-type solvent and water. The composition is useful as an additive for preventing functional deterioration of fluid catalytic cracking catalysts for heavy petroleum fractions. When it was allowed to stand at room temperature for 1 month it shows almost no precipitation [241]. 

Insoluble alkyl esters of phosphoric acid, especially tributyl phosphate. These phosphate esters have relatively poor foam control [536]. 

Alcohols react with phosphoric acid to yield alkyl phosphates ... 

Alkyl esters of phosphoric acid and phosphine oxides will extract metals and mineral acids by direct solvation. Tri-//-butyl phosphate (TBP) and tri- -octyl phosphine oxide (TOPO)... 

It is in the very nature of the catalytic process that the intermediate compound formed between catalyst and reactant is of extreme lability therefore not many cases are on record where the isolation by chemical means, or identification by physical methods, of intermediate compounds has been achieved concomitant with the evidence that these compounds are true intermediaries and not products of side reactions or artifacts. The formation of ethyl sulfuric acid in ether formation, catalyzed by HjSO , and of alkyl phosphates in olefin polymerization, catalyzed by liquid phosphoric acid, are examples of established intermediate compound formation in homogeneous catalysis. With regard to heterogeneous catalysis, where catalyst and reactant are not in the same... 

These compounds contain the fragment R as an alkyl or aryl moiety. In other words, they result from the esterification of an alcohol or a phenol with nitrous acid, nitric acid, phosphoric acid, sulfuric acid, or sulfamic acid, respectively. Many of the esters to be examined in this chapter must be activated prior to eliciting their effects, e.g., the organic nitrites and nitrates, which act as donors of nitric oxide or an analogous molecule, and phosphates, which are activated by hydrolysis or even by phosphorylation (antiviral agents). Sulfates are very seldom active or used as prodrugs, but they have significance as metabolites and as industrial xenobiotics. 

Materials and Method. Aqueous solutions of disodium alkyl phosphates were prepared by dissolving the corresponding acids in sodium hydroxide solutions. The alkyl phosphoric acids were synthesized by the reaction of pyrophosphoric acid with the respective alcohol in benzene at room temperature for A days. Details of the purification procedures are given elsewhere(7). 

In 2004, Terada and coworkers reported the first asymmetric phosphoric acid-catalyzed Friedel-Crafts alkylation (Scheme 8). Aldimines 11 reacted with commercially available 2-methoxy furan (20) in the presence of BINOL phosphate (/ )-3q (2 mol%, R = S.S-MeSj-C Hj) to provide access to A-Boc-protected 2-furyl amines 21 in high yields (80-96%) and enantioselectivities (86-97% ee) [19]. 

In 2007, two groups independently described asymmetric phosphoric acid-catalyzed Friedel-Crafts alkylations of indoles. While You et al. chose the conventional approach and employed imines as substrates (Scheme 11), Terada and coworkers came up with a different concept and used electron-rich alkenes as precursors (Scheme 49) [73]. Enecarbamates 125 reacted with indoles 29 in the presence of BINOL phosphate (R)-io (5 mol%, R = bearing 2,4,6-triisopropyl-... 

Akiyama and coworkers extended the scope of electrophiles applicable to asymmetric Brpnsted acid catalysis with chiral phosphoric acids to nitroalkenes (Scheme 57). The Friedel-Crafts alkylation of indoles 29 with aromatic and aliphatic nitroalkenes 142 in the presence of BINOL phosphate (7 )-3r (10 mol%, R = SiPhj) and 3-A molecular sieves provided Friedel-Crafts adducts 143 in high yields and enantioselectivities (57 to >99%, 88-94% ee) [81]. The use of molecular sieves turned out to be critical and significantly improved both the yields and enantioselectivities. 

Similarly, alkyl phosphates are formed with H3PO4, phosphoric acid. 

Problem 13.15 Supply equations for the formation from phosphoric acid of (o) alkyl phosphate esters by reactions with an alcohol, in which each acidic H is replaced and H O is eliminated (6) phosphoric anhydrides on heating to eliminate H,0. 4... 

Sulfuric acid (or phosphoric acid) is preferred as an acid catalyst for addition of water to alkenes because the conjugate base, HSO40 (or H2P04e), is a poor nucleophile and does not interfere in the reaction. However, if the water concentration is kept low by using concentrated acid, addition occurs to give sulfate (or phosphate) esters. The esters formed with sulfuric acid are either alkyl acid sulfates R—0S03H or dialkyl sulfates (R0)2S02. In fact, this is one of the major routes used in the commercial production of ethanol and... 

The chemistry of phosphate esters is more complicated than that of sulfate esters because it is possible to have one, two, or three alkyl groups substituted for the acidic hydrogens of phosphoric acid ... 

It is desirable to avoid errors in pH measurement, which limit the accuracy of the above NMR pH titration. If an NMR titration is applied to a mixture of two acids, HA and HA, each of whose chemical shifts, 6 and S, follows Equation (13), it is possible to eliminate pH from the two equations and replace it with n, the number of equivalents of titrant added. Thus Ellison and Robinson obtained Equation (14), where A = 6-6, A = 6 -6, A° = <5° -S °, and R = KJK1 20 Moreover, it is not necessary to prepare solutions of exact molarity, because n can be evaluated more readily as (6-6 )/(6° -6 ), from the variation of the chemical shift of HA during the titration. When R is near 1, this is approximately a parabolic dependence of A on n. The titration of a mixture of formic acid and 1802-formic acid permitted the evaluation of the lsO IE on acidity from the 13C NMR chemical shifts 6 and S of the carboxyl carbons. In practice, this involved fitting to the three parameters A-, A°, and R. This same equation was used with 31P chemical shifts to evaluate the lsO IE on the acidity of phosphoric acid and alkyl phosphates.21... 

In the alkylation of ethylbenzene with ethylene, with conventional acid catalysts under usual conditions,. veobutyl benzene is a byproduct. rec-Butylbenzene was detected when the reaction was carried out over catalysts such as supported phosphoric acid,189 ferric phosphate,189 or AICI3—NiO—Si02-190 When Nafion-H or AICI3 are used, no such byproduct is detected, probably due to fast dealkylation of sec-butylbenzene under the more acidic conditions. 

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