Alkyl phosphate mixtures

Figure 11.10 P-NMR spectrum of an alkyl phosphate mixture in CDCI3.

Garbodiimide Formation. Carbodiimide formation has commercial significance in the manufacture of Hquid MDI. Heating of MDI in the presence of catalytic amounts of phosphine oxides or alkyl phosphates leads to partial conversion of isocyanate into carbodiimide (95). The carbodiimide (39) species reacts with excess isocyanate to form a 2 + 2cycloaddition product. The presence of this product in MDI leads to a melting point depression and thus a mixture which is Hquid at room temperature. 

However, exclusive primary or secondary alkyl phosphates are seldom produced. That is due not only to the expenses of production but to the fact that in practical application the mixture of both esters combined with the rest of unreacted starting material often offers most interesting properties. Changing the molecular ratio of alcohol to P4O10 from 2 1 to 4 1 results in an increase of the secondary ester in the mixture from 35% to 65%. 

P. E. Chaplanov, A. D. Chemikov, O. G. Mironov, G. N. Semanov, A. G. Svinukhov, A. G. Yaremenko, F. V. Linchevskij, N. A. Melnik, 1. A. Murashev, and I. S. Akhmetzhanov. Removing oils and petroleum products from water surfaces—using mixture of oxyethylated alkyl-phenol, alkyl-phosphate and fatty acid diethanolamine. Patent SU 1325816-A, 1992. 

The highly electrophilic character of the POf ion would suggest a very unselective phosphorylation behavior. For example, the ratio of alkyl phosphate to inorganic phosphate obtained in hydrolyses of phosphoric esters in water/alcohol mixtures should reflect the molar ratio of water and alcohol. This is indeed found in numerous cases, e.g. in the hydrolysis of phenyl and 4-nitrophenyl phosphate monoanions 97) or of 4-nitrophenyl phosphate dianions 65) at 100 °C in methanol/ water mixtures of various compositions, as also in the solvolysis of the acetyl phosphate dianion at 37 °C 97) or of phosphoenol pyruvate monoanions 82). Calculations of the free energy of the addition reactions of water and ethanol to the POf ion support the energetic similarity of the two reactions 98) (Table 4). 

This technique has been used for the determination of polychlorobiphenyls, polychlorodibenzo-p-dioxins, polychlorodibenzofurans, alkyl phosphates, chlorinated insecticides, organophosphorus insecticides, triazine herbicides. Dacthal insecticide, insecticide/herbicide mixtures, mixtures of organic compounds and organotin compounds in soils, and polyaromatic compounds, polychlorobiphenyls, chlorinated insecticides and organotin compounds in non-saline sediments and anionic surfactants in sludges. 

An example of a 6-endo cyclization of an alcohol onto an alkene radical cation/phosphate anion pair has also been described (Scheme 22). In order to bring about fragmentation of the primary alkyl phosphate bond in this reaction it was necessary to work in a 1 1 mixture of benzene and acetonitrile [139,140],... 

The favored formation of a nucleoside 3 -(alkyl phosphate) was observed on treating the diphenyl phosphate anhydride of uridine 2, 3 -cyclic phosphate with benzyl alcohol.273 In a somewhat related reaction, on treatment with dicyclohexylcarbodiimide in aqueous pyridine, adenosine 2 (3 )-phosphate gave, initially, the 2, 3 -cyclic phosphate, which, on further reaction with the diimide, gave a mixture of the N-phosphonourea nucleoside 44 and its 2 -isomer, in unequal amounts.269 This type of reaction does not seem to occur with... 

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... 

At lower temperature, thermally generated film has more similarity to tribofilm. The thermal films, as in the case of the tribofilms, contain mostly a mixture of short-and long-chain polyphosphates. The chemical states of phosphorus and sulfur in each neutral and basic pair were very comparable. The aryl phosphate films contain long-chain polyphosphate throughout the film, whereas the alkyl phosphate films are composed of long-chain polyphosphates in the bulk. Also, the aryl polyphosphate films contain more unchanged ZDDP. 

Configurational assignment to cyclic [l80]phosphodiesters is made by alkylating the phosphate group to a mixture of axially and equatorially alkylated phosphate diesters. The triesters in Equation 9 exemplify the nature of the product mixture ... 

Alkyl phosphates, also coco based, are formed by the reaction of fatty alcohol with phosphorous pentoxide. The product is a mixture of monoesters and diesters. Its sodium salt (MAP) is reportedly mild and is used in facial wash, such as Kao s Biore. Other uses are as antistatics in textile auxiliaries, corrosion inhibitors, surfactant additives for extreme pressure (EP) lubricants, and surfactant components in alkali and acid cleaners. Coco-based alkyl polyglycosides (APG) have been successfully produced and marketed by Henkel in the United States. The alkyl polyglycoside fuUy satisfies the demand for a mild surfactant and is completely biodegradable. 

Both, alkyl phosphates and alkyl ether phosphates are made by treating the fatty alcohol or alcohol ethoxylates with a phosphorylating agent, usually phosphorous pentoxide, P4OJQ. The reaction yields a mixture of monoesters and diesters of phosphoric acid, with the ratio of the two esters being determined by the ratio of the reactants and the amount of water present in the reaction mixture. The physico-chemical properties of the alkyl phosphate surfactants depend on the ratio of the esters. Phosphate surfactants are used in the metal-working industry, due to their anticorrosive properties. 

Phosphoric and Polyphosphoric Acid Esters, R(OC2H4)xOP(0)(0 M+)2 and [R(OC2H4)xO]2P(0)0 M+ Mainly phosphated POE alcohols and phenols, some sodium alkyl phosphates (not oxyethylenated). The POE materials are available in free acid form or as sodium or amine salts. Products are mixtures of monobasic and dibasic phosphates. 

Ribonucleoside 2 3 -cyclic phosphate are far more liable toward alkali and acid than are the noncyclic phospho-diesters. Hydrolysis of ribonucleoside 2 3 -cyclic phosphate produces a mixture of 2 - and 3 -phos-phates in approximately equal amoimts. Acid- and alkali-catalyzed alcoholysis of these cyclic phosphates also produces a mixture of the 2 -and 3 -alkyl phosphates, - - and the reactions are apparently reversible. " This behavior is a rather general characteristic of five-mem-bered, cyclic phosphates. [[Six-membered, cyclic phosphates, namely (25), (28), and (28a), are relatively more stable. Phosphodiesterases have been employed for the convenient preparation of specific nucleoside 2 - or 3 -phosphates by selective cleavage of a particular 0-P linkage in nucleoside 2 3 -cyclic phosphates. ... 

Related reactions in the oxygen series were first observed only recently as complications in Michaelis-Arbuzov reactions. The 2-halo-alkyl phosphate and phosphonate esters which occur as intermediates in the Michaelis-Arbuzov reaction of certain cyclic phosphites and phos-phonites (cf. Section II-A-1) undergo an internal alkyl exchange reaction (eq. 4) (176). Although reaction of 8-bromoethyl acetate with triethyl phosphite is said to furnish the expected product, diethyl fi-acetoxyethylphosphonate, in 28% yield (220), reaction of this same alkyl halide with dimethyl phenylphosphonite (129) gave the expected methyl phenyl(/9-acetoxyethyl)phosphinate in not greater than 5% yield (eq. 6). Instead, the major products were d-acetoxyethyl phenyl-(methyl)phosphinate (60%) (12) and a mixture of ethylene bi [phenyl-(methyl)phosphinate], [CH20P(0)(Me)Ph]2, (13) and an, ester of... 

Preparation procedure. Tri-n-alkyl phosphate ((RO)3P(0)), titanium tetra-aUcyloxide (Ti(OR)4) and potassium alkyloxide (KOR) (R is n-alkyl Et, Pr, Bu) (all Aldrich GmbH) were used as starting reagents. The ROH alcohols were dried over magnesium alkyloxide and distilled before use. All synthesis stages were conducted in dry argon atmosphere. An equimolar mixture of (RO)2P(0)(OH) and Ti(OR)4... 

At the same time, surfactants like alkylbenzene sulfonates remain the most widely used basis for laundry detergents. Anionics remain the main products for making detergent compositions. Some of the application aspects of relatively new types of anionics (a-olefin sulfonates, sulfocarboxylic acids, alkyl phosphates etc.), whose commercial manufacture began in the 60-ties - 70-ties of the 20 century, are described by Stache [95]. The application of conventional types of nonionics like ethoxylated alcohols or alkyl phenols is presented in [13 -14], Alkyl polyglycosides were widely used in the last 5-8 years [96]. However, the main tendency in the development of new generation detergents is the use of surfactant mixtures in their optimum composition [97, 98]. 

However, definite primary or secondary alkyl phosphates are seldom produced in practice. There are two reasons for this. First, the production costs are generally too high, and secondly the mixture of both esters in combination with the unreacted starting material often offers the most interesting properties for practical applications. 

Enzyme samples (150 - 200 mg) were dialyzed extensively after labeling and chromatographed on Whatman CM-52 (2.5 x 25 cm) with 0.1 M phosphate, 0.100 M K, pH 5.7. Without the chromatographic purification step these samples also contained significant amounts of autolyzed forms which, while catalytically inactive, gave distinct spectral peaks in the NMR. Furthermore, the subsequent kinetic experiments required pure Met-192 alkylated enzyme, free of unalkylated native enzyme which was always residual in the alkylation reaction mixture. 

Sokolov et al. [26] have reported successful analysis of a mixture of pure sodium dodecyl sulphate and pure sodium dodecyl phosphate (mono- or diester not specified) by this method, and Ivanov et al. [27] analysed alkyl phosphates by titration of the column effluent with alkali to bromocresol green. 

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