Phosphoric acid esters Pyrophosphoric

Synonyms Bis-0,0-diethylphosphoric anhydride Diphosphoric acid, tetraethyl ester Ethyl pyrophosphate, tetra- Pyrophosphoric acid, tetraethyl ester TEP TEPP Tetraethyl diphosphate Tetraethylpyrophosphate Classification Phosphoric acid ester Empirical C8H20O7P2... 

Bromocyanoacetamide Mixed phosphoric acid esters and unsym. pyrophosphoric acid esters s. 18,171... 

Esters of phosphoric acid, pyrophosphoric acid, and triphosphoric acid are important biological molecules. Each OH group of the acid can be esterified monoesters and diesters are the most common biological molecules. ATP is a monoester of triphosphoric acid. We have seen that the components of cell membranes are monoesters or diesters of phosphoric acid (Section 16.13), and that many of the coenzymes are monoesters or diesters of either phosphoric acid or pyrophosphoric acid (Chapter 24). In Section 26.1, we will see that DNA and RNA are diesters of phosphoric acid. 

Nucleotides, in addition, carry phosphoric acid in ester linkage with the ribose (or deoxyribose) component. The 5 -esters are biologically important here the phosphoric acid (or pyrophosphoric or triphosphoric acid) is bound to the —CH2OH group of the sugar moiety (cf. ATP, uridine and cytidine diphosphate Chapt. Vl-5). 

Derivatives of phosphoric acid, pyrophosphoric acid, and related compounds are very important in biological systems. Pyrophosphoric acid is an anhydride of phosphoric acid. Adenosine triphosphate, an energy carrier that is universally found in living organisms, has a phosphorus dianhydride connected to an adenosine group by a phosphate ester linkage. Phosphorus ester bonds are used to form the polymeric backbone of DNA (see Chapter 27). 

DCC reacts rapidly and nearly quantitatively at 25° in ether solution with mono and di esters of phosphoric acid to yield the corresponding di or tetra esters of pyrophosphoric acid, with immediate precipitation of dicyclohexylurea. It appears... 

The main purpose of this section is to introduce derivatives of phosphoric acid. The acid chloride derivative is C1P0(0H)2, chlorophosphoric acid, and the amide derivative is phosphoramic acid, HgN-POCOHlg. These acid derivatives will not be discussed because they will not be used in this book. There are three ester derivatives of phosphoric acid a monoester 203, a diester 204, and a triester 205. There are also derivatives of pyrophosphoric acid (diphosphoric acid, 206), which include various esters. 

Pyrophosphoric and acylphosphoric acid esters, also phosphoric acid aryl esters from phosphoric acid vinyl esters s. U, 156... 

Phosphoric acid diesters from phosphorodichloridates—Simultaneous removal of protective groups s. 13, 284 Pyrophosphoric acid esters... 

A soln. of picryl chloride in acetonitrile added dropwise to a soln. of adenosine-5 -phosphoric acid and tri-n-butylamine in methanol-pyridine, and the product isolated as the NH4-salt after 2 hrs. at room temp. ammonium methyl adenosine-5 -phosphate. Y 84%.— The soln. remains homogeneous and no precipitates are formed, such as ureas when carbodiimides are used as reagents. F. e., also pyrophosphoric and cyclic phosphoric esters, s. R. Wittmann, B. 96, 2116 (1963). 

Corby, N S, Kenner, G W, and Todd, A R (1952) The preparation of tetra-esters and pyrophosphoric acid from diesters of phosphoric acid by means of exchange reactions. J. Chem. Soc. (Lond.) 1234-1243... 

Nucleotide derivatives. Dry adenosine-5 -phosphoric acid stirred with -carb-ethoxy-a-ethoxyvinyl diethyl phosphate and tri-n-butylamine in abs. dimethyl-formamide until dissolved after 2-3 days, dil. with acetone and the product precipitated with a soln. of anhydrous Nal in acetone Na P -(5 -adenosyl) P -diethyl diphosphate (Y 87 % as the monohydrate) warmed 3 hrs. at 50° in abs. methanol-pyridine, and the product isolated as the NH4-salt NH4 5 -adenosine methyl phosphate (Y 79.2% as the monohydrate).—Pyrophosphoric acid esters react with alcohols, amines, and acids so that the monoester part appears in the product. The adenosine-5 -phosphoric acid group in the intermediate triester is activated and can be easily combined with various nucleophiles. F. e. without isolation of the intermediate s. F. Cramer and R. Witt-mann. B. 9A, 328 (1961) s. a. B. 94, 322 dimethylformamide as phosphorylation catalyst s. B, 94, 989. 

Most of the coenzymes are esters of phosphoric or pyrophosphoric acid. The main reservoirs of biochemical energy, adenosine triphosphate (ATP), creatine phosphate, and phosphoenolpyruvate are phosphates. Many intermediary metabolites are phosphate esters, and phosphates or pyrophosphates are essential intermediates in biochemical syntheses and degradations. The genetic materials DNA and RNA are phosphodiesters. 

Non-metals and metalloids with medium electronegativity values (P, As, S and Se) form covalent compoimds in biological systems, such as esters of phosphoric, pyrophosphoric and tripolyphosphoric acids, sulfur amino acids and then-selenium analogues, arsenic analogues of amino compounds and sulfur heterocycles. 

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