Phosphoric acid phosphorodichloridate

Phosphonic acid, (phthalimidomethyl)-, diethyl ester, 65, 119 Phosphorazidic acid, diphenyl ester (26386-88-9), 68,1 Phosphoric triamide, hexamethyl- (680-31-9), 66, 51, 94 Phosphorodichloridic acid, 2-chloroethyl ester, 65, 68 Phosphorous acid, triethyl ester, 65, 108.119 Phosphorus oxychloride, 66,173, 176 67,1 68, 41,162 Phosphorus tribromide (7789-60-8), 67, 210 Phthalimide, N-(bromoethyl)-, 65, 119 Phthalimide, N-(hydroxymethyl)-, 65,119 Pig liver esterase, 69, 20... 

Although the treatment of a phosphorodichloridate with the tri-n-butylammonium salt of phosphoric acid seems a plausible route to nucleoside diphosphates, this has recently been shown instead to be a means of preparing the triphosphate.8 Probably the most reliable method for preparing diphosphates is that described by Poulter,9 in which the tetra-n-butylammonium salt of a nucleophilic phosphorus component, for example, pyrophosphate is reacted with a nucleoside 5 -tosylate in acetonitrile (Figure 9.2). 

PHOSPHORIC ACID, TRISODIUM SALT see SJH200 PHOSPHORIC ACID, TRITOLYL ESTER see TNP500 PHOSPHORIC BROMIDE see PHR250 PHOSPHORIC CHLORIDE see PHR500 PHOSPHORIC SULFIDE see PHSOOO PHOSPHORIC TRIS(DIMETHYLAMIDE) see HEKOOO PHOSPHOROCHLORIDOTHIOIC ACID-0,0-DIMETHYL ESTER see DTQ600 PHOSPHORODICHLORIDIC ACID, ETHYL ESTER see EOROOO... 

Cyclic phosphoric acid esters from phosphorodichloridates O... 

The cyclic product is extremely sensitive to moisture (hydrolysis) and was more readily isolated as the cyclic diester. An interesting correlation has been observed the phenyl triesters of high energy cyclic phosphates (cyclic nucleotides, ethylene phosphate) are very reactive species, susceptible to decomposition. On the other hand, the phenyl triesters of low energy cyclic phosphates are stable, crystalline compounds. Hence, for example, the phenyl triester of trimethylene phosphoric acid is a crystalline compound readily prepared in high yield by reaction of 1,3-propanediol with phenyl phosphorodichloridate. 

Phosphoric acid esters from phosphorodichloridates OPOGlg OPO(OR)2 s. 13,165... 

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

Phosphorylation. Phosphorus oxychloride reacts with alcohols, amines, and thiols, resulting in phosphorylation of these functional groups. Trimethyl phosphate is a particularly effective solvent, and tertiary amine bases are generally used as well. Treatment of primary alcohols with POCI3 results in the formation of phosphonyl dichloride intermediates which, in the presence of excess alcohol, convert to symmetrical trialkyl phosphates. It is generally possible to isolate aryl phosphorodichloridates when a two-fold excess of (1) is used and AICI3, KCl, or pyridine is used as a catalyst. Secondary and tertiary alcohols tend to form alkyl chlorides and phosphoric acid. 

Phosphorus oxychloride is a suitable reagent for preparation of the symmetrically substituted phospho-triesters of type (RO)3PO. The preparation is easily achieved by treatment of phosphorus oxychloride with 3 equiv. of alcohols or their metal salts. The reaction is generally promoted by a base or acid. Titanium trichloride is a particularly effective catalyst for the reaction. Conversion of POCI3 to unsymmetri-cally substituted phosphotriesters is achievable with difficulty. Phosphorochloridates and phosphorodichloridates have been used for the preparation of mixed tertiary phosphoric esters of type (ROlmPOfOROn (ffi = 1, n = 2, or m = 2, n = 1) in a very wide variety. Reaction of phosphorus oxychloride and 1 or 2 equiv. of alcohols followed by hydrolysis forms phosphomonoesters or phosphodi-esters, respectively. The hydrolysis may be generally effected by dilute aqueous alkali. Some phosphoFodichlori te intermediates are easily hydrolyzed by water. For example, the phosphorylation of a ribonucleoside (1 equation 4) with phosphorus oxychloride in an aqueous pyridine-acetonitrile mixture furnishes the nucleoside S -monophosphate (2) in excellent yield. ... 

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