Hydrolysis triethyl phosphate

Phosphates. Insoluble orthophosphates may be precipitated with phosphate ion derived from trimethyl or triethyl phosphate by stepwise hydrolysis. Thus 1.8M sulphuric acid containing zirconyl ions and trimethyl phosphate on... 

The cyclization of compound 258 in triethyl phosphate at 220°C for 20-30 min in the presence of potassium carbonate, followed by alkaline hydrolysis at 90°C for 1 hr, gave oxolinic acid in 75% yield (70MIP1 77TL4545). Oxolinic acid was also prepared by reacting 3,4-methylenedi-oxyaniline and EMME with triethyl phosphate under the previous conditions. 

Anion or cation generation Anions can be generated slowly in solution to bring about homogeneous precipitation. Swift and Butler reviewed precipitation of the metal sulfides by use of thioacetamide or thiourea. PFHS of sulfides of cadmium, mercury, zinc, and nickel have been studied more recently by Swift and others. Phosphate can be generated by hydrolysis of triethyl phosphate, oxalate by hydrolysis of methyl oxalate, and sulfate by hydrolysis of diethyl sulfate or sulfamic acid. 

The preparation of dialkyl 1-alkynylphosphonates by an appropriate P-elimination procedure was first recorded in 1957, when it was reported that the action of EtONa on diethyl 2-[3-(diethoxyphosphinyl)propenyl] phosphate in refluxing EtOH leads to diethyl 1-propynylphosphonate in 69% yield (Scheme 1.13). The experimental conditions are crucial, and it has been shown that successful elimination of phosphate takes place to the exclusion of the ethanolysis reaction only at elevated temperature. At room temperature, diethyl 2-[3-(diethoxyphosphinyl)propenyl] phosphate is reported to undergo competing ethanolysis to triethyl phosphate and diethyl 2-oxo-propylphosphonate. Because of the drastic reaction conditions required for the subsequent conversion to 1-alkynylphosphonates, this method was rarely used and remained underdeveloped for a sigiuficant period of time. Fortunately, many efforts have been made to discover bases that might cause elimination of the phosphate from the enol without also bringing about isomerization or hydrolysis. The development of a variety of milder alternative methods has led to the much more widespread adoption of this elimination sequence. ... 

In water at pH < 7.0 the hydrolysis of triethyl phosphate proceeds by water attack on the CHg group, and there is no acid catalysis observed up to 0.5 mol 1 in contrast, an acid-catalysed mechanism, Aaj2, does appear to operate in 35% dioxan-water.2 Hydrolysis of some dimethyl vinyl phosphates (26) by... 

Neutral phosphate triesters will readily undergo acid or base-catalyzed hydrolysis with alkyl and/or phosphoryl fission. For example, trimethyl and triethyl phosphate will undergo hydrolysis in neutral water via an Sn2... 

Caldum oxide was introduced into the composition using calcium nitrate tet-rahydrate and phosphate through the hydrolysis of triethyl phosphate (TEP). The... 

Selective reduction of 4,4-dichloropyrazol-3-ones 673 has been accomplished in a two-step process involving first reaction with triethyl phosphite followed by alkaline hydrolysis of the intermediate phosphate ester 674. 4-chloropyrazol-3-ones 675 were obtained in yields ranging from 60-80% (77USP4021445) (Scheme 197). 

Salicylaldehyde and triethyl phosphite upon heating gave, instead of the expected diphosphonate (20), the rearranged phosphate-phosphonate (21). A new method to obtain 1-aminoalkylphosphinic acids (22) has been published it involves addition of bis(trimethylsilyl) phosphonite to Af-trityl imines, followed by hydrolysis. A similar reaction of bis(trimethylsilyl) phosphonite with 1-pyrroline trimer gave 2-pyrrolidinylphosphinic acid in 90% yield. Bis(trimethylsilyl) phosphonite with carbamoyl chlorides and triethylamine gave fair yields of the carbamoylphosphonites (23). ... 

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