Phosphoric phosphorylation with

Phosphoric Acid-Based Systems for Cellulosics. Semidurable flame-retardant treatments for cotton (qv) or wood (qv) can be attained by phosphorylation of cellulose, preferably in the presence of a nitrogenous compound. Commercial leach-resistant flame-retardant treatments for wood have been developed based on a reaction product of phosphoric acid with urea—formaldehyde and dicyandiamide resins (59,60). 

Proceeding from 5 -0-acetylazauridine (80), a mixture of 2 - and 3 -monophosphates (81, 82) was prepared by phosphorylation with polyphosphoric acid, and these were converted into the 2, 3 -cyclic phosphate (83). From the 2, 3 -0-isopropylidene derivative of 3-methyl-6-azauridine the 5 -phosphate was prepared by treatment with cyanoethylphosphate and the corresponding diphosphate from its morpholidate through the action of phosphoric acid. ° Furthermore, a diribonucleoside phosphate (85) with a natural 3 -5 internucleotide linkage was prepared from 6-azauridine, The starting material for the preparation of such derivatives was 5 -0-acetyl-2 -0 -tetrahydro-pyranyluridine-3 -phosphate (84) which was condensed with di-G-acetylazauridine (86) or with 2b3 -0-isopropylidene-6-azauridine (76) with the aid of dicyclohexylcarbodiimide. ... 

Preparation of 6-azacytidine-5 -phosphate by direct phosphorylation with cyanoethylphosphate was not successful. The substance could be prepared, however, on ammonia treatment of 4-thio-6-azauridine-5 -phosphate which was obtained by phosphorylation of 2, 3 -isopropyl-iden-4 thio-6-azauridine with pyrophosphoryl chloride. From mor-pholidate of 6-azacytidine-5 -phosphate, 6-azacytidine-5 -diphosphate was prepared by the action of phosphoric acid. ... 

O-isopropylidene derivative (10) was then phosphorylated with phosphorous oxychloride to form the phosphate ester (11) from which the protecting groups were removed by mild acid hydrolysis. The 3-phos-phate (15) was obtained by phosphorylating the 4,6-benzylidene derivative (13) of the same glycoside with phosphorus oxychloride, followed by hydrolytic removal of the protecting groups, from the ester (14) thus obtained. 

The phosphorylation of OH-containing nonionic surfactants with P4O,0 gave a mixture of mono- and diesters of phosphoric acid with the surfactants. The optimum surfactant/P4O10 ratio was 2.5-3 1. The yield of mono- and diesters did not depend on the reaction temperature but was significantly influenced by the water content of the starting materials [7]. 

A. Synthetic Methods.—There have been no strikingly new approaches to the general problem of phosphorylation, but several ingenious methods of preparing suitable active esters under mild conditions have been reported. Typical of these is the reactive intermediate (1) formed from reaction of a mono- or di-ester of phosphoric acid with (2), itself produced by reaction of triphenylphosphine with bis(2-pyridyl) disulphide (preferably in the presence of mercuric ion as scavenger for the 2-mercaptopyridine liberated). 

Analogues of phosphatidyl ethanolamine, phosphatidyl choline, and phosphatidic acid with pantoic acid skeleton were prepared by phosphorylation with the respective phosphoric mono-, bis-, and tristriazolide [17]... 

Phosphates of pharmaceutical interest are often monoesters (Sect. 9.3), and the enzymes that are able to hydrolyze them include alkaline and acid phosphatases. Alkaline phosphatase (alkaline phosphomonoesterase, EC 3.1.3.1) is a nonspecific esterase of phosphoric monoesters with an optimal pH for catalysis of ca. 8 [140], In the presence of a phosphate acceptor such as 2-aminoethanol, the enzyme also catalyzes a transphosphorylation reaction involving transfer of the phosphoryl group to the alcohol. Alkaline phosphatase is bound extracellularly to membranes and is widely distributed, in particular in the pancreas, liver, bile, placenta, and osteoplasts. Its specific functions in mammals remain poorly understood, but it seems to play an important role in modulation by osteoplasts of bone mineralization. 

For the regeneration of ATP, we chose the system based in the use of acetyl phosphate as final phosphoryl donor because this affords several advantages (i) acetyl phosphate is easily obtained by acylation of phosphoric acid with acetic anhydride in ethyl acetate [24], and (ii) the resulting sodium acetate is a non-toxic and an environmentally compatible compound. However, this regeneration system is quite sensitive to pH changes. Thus, a continuous adjustment of the pH to 7.5 is needed to maintain the proper operation of the system. Perhaps the main aspect of this approach is that the DHAP must be formed at the same rate as it is consumed by the aldolase. To avoid the accumulation of DHAP and minimize its non-enzymatic degradation, fine tuning of the aldolase/DHAK activities is needed. This adjustment must be experimentally optimized for some acceptors. 

The rate of phosphorylation with the amide of propyleneglycolphos-phorous acid is somewhat higher than with the amide trf ethyleneglycol-phosphorous acid. The treatment erf cellulose with the cyclic dimethyl-amide of propyleneglycolphosphorous add produced intermediate cel-lulofe phosphites with a phosphorus content of up to 16% (DS = 1.92). 

Examples of chemical phosphorylation with phosphorous (V) reagents... 

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. 

As pyrimidine nucleosides are rather stable under acidic conditions, they may be phosphorylated with a mixture of 85% phosphoric acid and phosphorus pentaoxide ( polyphosphoric acid )- The 2, 3 -0-isopropylidene acetals of uridine and of cytidine were treated with polyphosphoric acid for two hours at 60°. After acid hydrolysis, the 5 -phosphates of these nucleosides were obtained in good yield. 2, 3 -0-Benzylidenecytidine was phosphorylated similarly to cytidine 5 -phosphate. The polyphosphoric acid method was also used to convert the 2, 3 -0-isopropylidene acetals of 5-bromouridine, 3-methyluridine, and A -methyl- and A -dimethyl-cytidine into their respective nucleoside 5 -phosphates. 

Cyclic derivatives of phosphoric acid with chiral amino alcohols, e.g., 71, have been used as chiral electrophilic animation reagents (Section D.7.I.). As an example of such a compound, the reaction of (—)-ephedrine with phosphoryl chloride is given. 

Phosphorylation by treatment of nonylphenol in concentrated phosphoric acid with phosphorus pentoxide has been described in the derivation of surfactants based on the phosphate group (ref. 36). 

In both oases, the functionality of the phosphorus oxychloride compound is reduced by hydrolysis after esterification with the phenolic compound. The reaction of monophenyl phosphoric acid with 1,3,5,7-tetiaazatricyclo [3.3.3.P ]decane can produce linear or crosslinked products [179]. The phosphorylated phenolic resin synthesized as desoribed in Scheme 30 can be brominated at the ortho and para positions not blocked during polymerization. These phosphorylated j enohc resins have a bromine eontent of 43% [179], In analogy with the reactions described in Scheme 29,2,4,6-tribromophenol... 

Nada et al. studied the influence of the corn cobs treatment, before phosphorylation, with different concentrations of the NaOH solution upon the phosphorylation efficiency and upon the metal ions adsorption. They demonstrated that the use of a 7.5% NaOH solution lead to the highest level of phosphate groups which were incorporated into the treated corn cobs. The modified cellulose was washed several times with distilled water (and maybe acetone, or an alcohol), dried, and then could be used in further experiments. In the phosphorylation process the phosphoric group should be introduced at the primary carbon with hydroxyl groups and the phosphorylation is complete when all the C-OH groups are substituted. ... 

Initially, the Cj position of the ribose-5-phosphoric acid (ribose-5-phosphate) unit is activated by phosphorylation with ATP, and it becomes 5-phospho-D-ribosyl-l-pyrophosphoric acid (PRPP).This pyrophospho-ric acid unit is replaced with an activated ammonia derived from a glutamine with inversion of the stereoconfiguration at the Cj position. It is this nitrogen atom that subsequently becomes N-9 of the purine base. 

The cyclization of 5-(2-carboxyanilino)pyrimidine (170) with sulfuric acid/phosphoric acid leads to the 7-chloropyrimido[5,4-A]quinolinetriones (171) (57JCS4997, 74KGS131), the 2,4,10-trichloro compounds being obtained with phosphoryl chloride (72JHC91), whilst a formally similar cyclization of 4(6)-arylamino-5-ethoxycarbonylpyrimidines gives... 

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