Methyl orthophosphoric acid

Synonyms methyl orthophosphoric acid methyl acid phosphate Methyl Salicylate... 

Synonyms Methyl orthophosphoric acid Methyl phosphoric acid Phosphoric acid, monomethyl ester... 

Methyl orthophosphoric acid. See Methyl acid phosphate... 

Methyl orthophosphoric acid. See Methyl acid phosphate Methyloxacyclopropane Methyloxirane S(>)>Methyloxirane. See Propylene oxide... 

Orthophosphoric Acid may be titrated with sodium or potassium hydroxide free from carbonate. The equivalent point indicating NaH2P04 occurs at pH = ca. 4-2, which is within the transition range of methyl yellow, methyl orange and bromophenol blue. The endpoint tint should be matched against that of a comparison solution containing about the same concentration of NaH2P04. 

It was recently shown12) that in radical polymerization the chain termination rate constant is observed to decrease with the introduction of a polyfunctional complex-ing agent into the system. An especially sharp decrease of the termination rate, up to the formation, under certain conditions, of living radical polymerization centers, was noted in the methyl methacrylate-orthophosphoric acid system. 

Benzyl-1-indanol 32, readily available in a few steps from 1-indanone, has been converted into 2-benzylindene 33 in various ways [66 - 68]. Treatment of 32 with orthophosphoric acid in chlorobenzene, for example, gives 33 as the sole product. However, use of polyphosphoric acid in the same solvent effects clean cyclodehydration of both 32 and 33 giving the mono-/uso-diindane 34 in high yield [65]. Several cenfro -alkylated derivatives of 34, including the methyl... 

The methyl homologue, 1-hydroxy-3-methylxanthone, has been synthesised in 3 % yield from equimolar proportions of salicyloylurea and orcinol in the presence of orthophosphoric acid, phosphorus oxychloride and anhydrous zinc chloride by heating at 150 C for 5 hours (ref. 125). 

Orthophosphoric acid is a tribasic acid giving rise to three series of salts primary orthophosphates, e.g. NaH2P04 secondary orthophosphates, e.g. Na2HP04 and tertiary orthophosphates, e.g. Na3P04. If a solution of orthophosphoric acid is neutralized with sodium hydroxide solution using methyl orange as indicator, the neutral point is reached when the acid is converted into the primary phosphate with phenolphthalein as indicator, the solution will react neutral when the secondary phosphate is formed ... 

Methyl 3-benzamido-4,6-0-benzylidene-3-deoxy-a-D-altropyranoside treated with dicyclohexylcarbodiimide and anhydrous orthophosphoric acid in dimethyl... 

Abbreviations DMSO, dimethyl sulfoxide, methyl sulfoxide, sulfinylbis[methane] TFA, trifluoroacetic acid, perfluoroacetic acid H3PO4, phosphoric acid, orthophosphoric acid ACH, acetic acid (glacial). 

A stirred mixture of 3-methyl-3-buten-2-one, trimethyl orthoformate, and some orthophosphoric acid heated with slow distillation of methyl formate during 7 hrs. followed by distillation of methanol, and the residue treated 5 min. with dil. HGl at room temp. -> 4-methoxy-l,5-dimethylbicyclo[2.2.2]oct n-2-one. Y 72%. F. e. s. K. Morita and Z. Suzuki, Tetrah. Let. 1964, 263. 

The alkylation of benzene by propan-l-ol and AICI3 in hexane or cyclohexane has been studied over the temperature range -40 to -f-100°C by n.m.r. spectroscopy. Structures of the several products of alkylation of mesitylene with 3,5-di-t-butyl-4-hydroxybenzyl alcohol and of resorcinol and its methyl ethers with a-butylbenzyl alcohol plus orthophosphoric acid have been elucidated. Allylation of guaiacol by allyl alcohol and an acid catalyst is... 

Figure 3.2 Separation of fatty acid methyl esters by gas-liquid chromatography on a 2mx4mm column. Stationary phase 10% polyethylene glycol adipate (stabilized with orthophosphoric acid) on Diatomite C-AAW. Carrier gas argon. Flow rate 50ml/1 min. The oven temperature was programmed from 65°C to 185°C at 8°C per min. The sample consists of fatty acids derived from a milk diet for calves. Heptanoic and heptadecanoic acids were added as internal standards in concentrations of 1.55 mg 7 0 and 4.94 mg 17 0 in 10 ml sample solution and the computer was programmed to print out the concentration in mg/10 ml of each fatty acid In the mixture. IS = internal standard BHT = butylated hydroxytoluene (antioxidant). Reproduced with kind permission of Mr J.D. Edwards-Webb.

Orthophosphoric and benzylphosphonic acids have been selectively alkylated with triethyl phosphite in a new synthesis of mono-, di-, and triethyl phosphates and of mono- and di-methyl phosphonates.62 A-Methylol carboxamides and sulphonamides react with trialkyl phosphites to give the phosphonate derivatives (78) and (80), respectively.63 However, the mechanism appears to be quite different in each case while the carboamides react by a transesterification-rearrange-ment pathway, the sulphonamides undergo elimination-addition via the imine (79). 

Typical procedure. Methyl Z3-0-isopropyUdene-fi-D-ribo-pentodialdo-l,4-furanoside 1870 [1391] A solution of anhydrous crystalline orthophosphoric add (0.98 g, 10 mmol) in dimethyl sulfoxide (2.0 mL) was added to a solution of methyl-2,3-O-iso-propylidene-/ -D-ribofuranoside (4.08 g, 20 mmol), pyridine (0.8 mL, 10 mmol), and DCC (12.4 g, 60 mmol) in dimethyl sulfoxide (50 mL). The mixture was kept at around 25 °C for 3 h by occasional ice-cooling, then diluted with ethyl acetate (100 mL), and a solution of oxalic acid dihydrate (5.04 g, 40 mmol) in methanol (10 mL) was added. The mixture was subsequently poured into saturated sodium chloride solution (200 mL), filtered, and the aqueous phase was extracted with ethyl acetate (100 mL). The combined organic phases were washed successively with dilute sodium hydrogen carbonate solution (100 mL), saturated sodium chloride solution (2 X 100 mL), and iced water (100 mL). The organic phase was dried with magnesium sulfate, concentrated under reduced pressure, and the residue was dissolved in ethyl acetate (25 mL) and filtered to remove residual N,N -dicyclohexylurea. The solution was concentrated to a syrup (4.7 g), which was purified by sublimation at 60-70 °C (0.1 Torr) to give the product 1870 as a white crystalline solid, 3.23 g... 

Acid phosphatases (Aps) are enzymes with a low pH that catalyze the hydrolysis of orthophosphoric monoester to alcohol and H3PO4. This enzyme has been utilized to a limited extent for the detection of pesticides through inhibition of the enzyme. AP was used with another enzyme, glucose oxidase (GOD), in abi-enzymatic biosensor for the determination of malathion, methyl parathion, and paraoxon. Biocatalytic hydrolysis of glucose-6-phosphate in the presence of acid phosphatase was reversibly... 

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