Phosphorous acid monoesters

HO A phosphoric acid monoester HO A phosphoric acid diester 0 1 R" A phosphoric acid triester A carboxylic acid ester... 

But neutralized phosphorous acid monoesters of alcohols were found to have detergent and plasticizing properties [60,74]. They can be obtained by reaction of phosphorous trichloride and fatty alcohols in equimolar ratios followed by saponification of the unreacted chlorine atoms of the dichlorophosphites with a base see Eqs. (26) and (27). 

On the other hand, phosphorous acid monoesters of lower alcohols easily undergo transesterification [75]. A preferred starting material is the triester of ethylene chlorohydrin, obtained by reaction of phosphorus trichloride with ethylene oxide, according to Eq. (28). 

Manufacture of highly water-absorbent polymers with uniform particle size and good flowability can be carried out by reverse phase suspension polymerization of (meth)acrylic acid monomers in a hydrocarbon solvent containing crosslinker and radical initiator. Phosphoric acid monoester or diester of alka-nole or ethoxylated alkanole is used as surfactant. A polymer with water-absorbent capacity of 78 g/g polymer can be obtained [240]. 

The outlined scheme can also be used to calculate the amount of phosphoric acid triesters. In that case the difference must be formed of the total phosphorus content minus that of free phosphoric acid, phosphoric acid monoester, and phosphoric acid diester. The resulting value is then multiplied with the calculated molecular mass of the triester. 

Another route to such nucleoside diphosphates starts from imidazolides of phosphoric acid monoester and nucleoside phosphates ... 

Acid phosphatase (acid phosphomonoesterase, EC 3.1.3.2) also catalyzes the hydrolysis of phosphoric acid monoesters but with an acidic pH optimum. It has broad specificity and catalyzes transphosphorylations. Acid phosphatases are a quite heterogeneous group with monomeric, dimeric, larger glycoprotein, and membrane-bound forms. Acid phosphatase activity is present in the heart, liver, bone, prostate, and seminal fluid. Prostate carcinomas produce large quantities of acid phosphatase, and the enzyme is, therefore, used as a biomarker [141]. 

There are comparatively few studies addressing the structure-metabolism relationships of phosphoric acid monoester hydrolysis. For example, kinetics of decomposition in rat whole blood were examined for the phosphoric acid monoesters of estrone, 17a- and 17/J-testosterone, 3-(hydroxyme-thyl)phenytoin (see Fig. 9.7,a), and 1-phenylvinyl alcohol (9.28, the enolic form of acetophenone) [87]. As a general trend, the rate of hydrolysis increased with the acidity of the leaving hydroxylated compound. In other words, hydrolysis was the fastest for the phosphoric acid aryl monoester (estrone 3-phosphate), and slowest for the two testosterone phosphoric acid... 

The prodrugs discussed in the previous section were obtained by esteri-fying a OH group in an active agent with phosphoric acid. A few comparable cases exist where the esterifying agent is not phosphoric acid, but a phosphoric acid monoester or diester. However, most examples presented in this section are either ... 

Phosphoric acid, H3PO4, is a tribasic (three-protic) acid—i. e., it contains three hydroxyl groups able to donate H"" ions. At least one of these three groups is fully dissociated under normal physiological conditions, while the other two can react with alcohols. The resulting products are phosphoric acid monoesters (R-O-P(O)O-OH) and diesters (R-0-P(O)O-O-R ). Phosphoric acid monoesters are found in carbohydrate metabolism, for example (see p.36), whereas phosphoric acid diester bonds occur in phospholipids (see p. 50) and nucleic acids (see p. 82 ). 

In any reaction where the cleavage of a carbon-hydrogen bond is important, the introduction of a metal ion into the molecule in the proper position will facilitate reaction. For example, in the elimination of the elements of a phosphoric acid monoester from the molecule below, the electrostatic attraction of the cupric ion facilitates removal of the proton on the o -carbon atom with subsequent elimination of the phosphoryl residue (8). 

Synthesis of Phosphonamidates from Phosphoric Acid Monoesters... 

When polyvinylalcohol is modified with phosphorous acid (monoesters are formed and also possibly some crosslinks), the dehydration is accelerated and occurs at lower temperatures [206]. 

Acetonitrile s. under CHgOCH Cl Monochloromethyl ether acetonitrile Sym. pyrophosphoric acid diesters from phosphoric acid monoesters... 

Phenyi dichlorophosphate intermediate, phosphoric acid monoester seiective prod. 

Dicyclohexylcarbodiimide Mixed phosphoric acid diesters from phosphoric acid monoesters... 

Trimethylchlorosilanel2,2 -dipyridyl disulfide Phosphoric from phosphorous acid monoesters Nucleotides s. 21,145 suppl. 31... 

Isooctylphosphate Mixtures of phosphoric acid monoester sodium salt, and phosphoric acid diester sodium salt Phosphoric acid monoester sodium salt 30 %, di-iso-octylphosphate 70 % Products of reaction of P2O5 and alcohol 1-10 % solution... 

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