Diethyl phosphite

N. N-diakyl amino Ethylamme Dibiitylphosphite Dicyandiamide Diethylammo ethanol Diethyl phosphite Diethyl sulfate Diketene... 

Partial control of enolate geometry occurs also when the enol phosphate, prepared by treatment of fluoroalkyl ketones with sodium diethyl phosphite, is... 

The decomposition of di- e -butyl peroxide in the presence of diethyl phosphite and an aromatic substrate leads to free-radical phosphination, Eqs. (43) and (44). 

This reaction also takes place with halogenides of dibasic acids. Thus adipoyl chloride and diethyl phosphite are reacted at 90°C for 8 h yielding adipyl-diphosphonic acid diethyl ester, according to Eq. (41). 

The following reaction sequence was used to obtain methyl hydroxymethanediphosphonic acid. This compound is widely used as a water hardness sequestering agent and detergent builder. Triethyl chloride was reacted with acetyl chloride to give diethylacetylphosphonate, followed by a conversion with diethyl phosphite and sodium. After completion of this reaction the substance was hydrolyzed with HC1 to yield hydroxymethanediphosphonic acid, [93,94], as shown in Eqs. (49)-(51) ... 

In a similar reaction of ketene with diethyl phosphite in the presence of boron fluoride etherate as catalyst, diethyl 1-acetoxyvinylphosphonate is formed [113] see Eq. (69) ... 

Another method for the preparation of hydroxyalkanephosphonic acids is the conversion of aldehydes with dialkyl phosphites in the presence of triethylamine or sodium methylate leading directly to the corresponding a-hydroxyalkane-phosphonates. This reaction is reversible, leading to the starting materials aldehyde and diethyl phosphite again [143,146]. 

Oleic acid, linolic acid, ricinolic acid, and 2-bromostearic acid methyl ester as well are reacting with diethyl phosphite in the presence of benzoyl peroxide to the corresponding phosphono fatty acid esters [156-158]. 

Stable HHTs such as the A -benzyl derivative 22, when reacted with neat diethyl phosphite under fairly forcing conditions, gave the desired a-aminomethylphosphonate... 

These results contrasted sharply with those obtained with a HHT that was relatively unstable to the reaction conditions. For example, the commercially available HHT of glycinonitrile 28 gave a very poor yield (6%) of coupled glyphosate product with diethyl phosphite because the reaction must be run with acid-catalysis at much lower temperatures (27,38). Somewhat higher yields were observed when 28 was used directly under the modified, acidic Mannich conditions to provide iV-phosphonomethylglycinonitrile 29, which was hydrolyzed direedy to GLYNa3 (39). 

Another AMPA-derived procedure took advantage of the neat reaction between the N-carbamoyl-HHT 59 and diethyl phosphite catalyzed by boron trifluoride etherate to generate the AMPA carbamate 60. Subsequent alkylation with ethyl bromoacetate and base produced the glyphosate triester carbamate 61, which was hydrolyzed to GLYH3 (59). 

The herbicide activity ascribed to the 1,2,4-oxadiazole derivative 67 (60) has prompted the search for other biologically active derivatives. This example was prepared from the corresponding 5-chloromethyl-1,2,4-oxadiazole 63 via conversion to the HHT 65 through the aminomethyl analog 64. Reaction of the HHT 65 with diethyl phosphite under neat conditions produced the desired diethyl ester intermediate 66, which was hydrolyzed to 67. 

The rigid, planar pyridine analog 111 was isolated in low yield by first hydrolyzing the known (67) pyridine diethyl phosphonate 109 to the corresponding free acid 110 followed by permanganate oxidation (2). An alternative synthesis of 111 has recently been reported (68). Alkylation of pyridine-2-carboxylate -oxide with dimethylsulfate and subsequent reaction with the sodium salt of diethyl phosphite gave the triester 112, which was readily converted to 111. 

The related phosphonoproline 115 has also been reported as a mixture of diastereomers from the addition of diethyl phosphite to the imine 113 followed by acidic hydrolysis of the intermediate triester 114 (69). 

Potassium cyanide, 56, 20 Potassium diethyl phosphite, 58, 135, 138 Potassium 1,1,1,3,3,3-hexafluoro-2-phenyl-... 

Japanese workers have prepared diethyl phosphite in 43% yield from the reaction of white phosphorus with ethanol and oxygen. 

Addition of diaUcyl phosphites HP(0)(0R)2 to terminal alkynes led to the formation of bis-phosphonates in 47-90% yield. These products result from addition of two P-H bonds across the C=C triple bond. Interestingly, although diethyl phosphite gave good results, the isopropyl derivative gave lower yields, and only mono-... 

Metal-catalyzed asymmetric addition of dialkyl phosphites to aldehydes (Pudovik reaction) has been extensively developed since the initial reports in 1993 by Shibuya. Scheme 5-25 illustrates the use of TiCh to promote diastereoselective addition of diethyl phosphite to an a-amino aldehyde. 

The use of chiral titanium complexes as catalysts is also possible. As shown in Scheme 5-26, the Sharpless titanium catalyst gave ees up to 53% for the addition of diethyl phosphite to benzaldehyde. 

The functionalized benzaldehyde derivative in Scheme 5-41 underwent diastere-oselective addition of diethyl phosphite catalyzed either by LLB (75 25 ratio of di-astereomers) or ALB (80 20 ratio) [30]. 

SRNl substitution include ketone enolates,183 ester enolates,184 amide enolates,185 2,4-pentanedione dianion,186 pentadienyl and indenyl carbanions,187 phenolates,188 diethyl phosphite anion,189 phosphides,190 and thiolates.191 The reactions are frequently initiated by light, which promotes the initiating electron transfer. As for other radical chain processes, the reaction is sensitive to substances that can intercept the propagation intermediates. 

Schrader prepared the ester (38) in 60% yield by reaction of sodium p-nitrophenate with diethyl chlorophosphate, using xylene as solvent for the reaction. He made it, but in lower yields, from p-nitrophenol and diethyl chlorophosphate, using, respectively, pyridine and sodium cyanide as acceptors for hydrogen chloride. Schrader also prepared it in 96% yield by nitrating diethyl phenyl phosphate at 0° C. or below. Under the conditions he used, Schrader claims that the nitro group is directed to the para position. No yield is given for the diethyl phenyl phosphate, which he presumably made from sodium phenate and diethyl chlorophosphate. Diethyl chlorophosphate may be prepared in high yield (30) from diethyl phosphite and chlorine. 

The broad use of A -carbonyldiimidazole (CDI) for the synthesis of amide and peptide linkages became a routine method only in the early sixties. JV-Protected amino acids were treated at room temperature with an equimolar amount of CDI to give imidazolides. Anhydrous tetrahydrofuran, dimethoxyethane, dichloromethane, pyridine, dimethylfor-mamide, and diethyl phosphite were utilized as solvents. In the second step the esters of amino acids, their hydrochlorides, or sodium salts were added to yield the peptide after several minutes or hours of reaction time. 

Diethanol Sulfide Diethanolamine Diethanolethylamine Diethanolmethylamine Diethoxyethylphosphine Oxide Diethoxymethylphosphine Oxide Diethoxyphosphine Oxide Diethyene Disulfide Diethyl Acid Phosphate Diethyl Ethanephosphonate Diethyl Ethylphosphonate Diethyl Hydrogen Phosphate Diethyl Hydrogen Phosphite Diethyl Hydrogen Phosphonate Diethyl Isopropylphosphonate Diethyl Methanephosphonate Diethyl Methylphosphonate Diethyl Phosphate Diethyl Phosphite Diethyl Phosphonate Diethyl Phosphoric Acid Diethyl(2-hydroxyethyl)amine Diethyl(/S-hydroxyethyl)amine Diethylaminoethanol Diethylethanolamine Diethylfosfit... 

Addition of triethyl phosphite to a-halosubstituted ketones has been reported to provide the a,P-epoxyphosphonate (as the diester) in reasonable yield (51%).346 Similar results were obtained using diethyl phosphite under basic conditions.346 347... 

The addition of anionic forms of trivalent phosphorus reagents (diethyl phosphite or diphenylphosphinite) to quinonemethides bearing two phosphoryl linkages on the exocyclic double bond provides a,a,a-triphosphoryl species (Equation 3.32).451... 

Reaction of the conjugate base of diethyl phosphite with 3-car-boxyethyl-substituted 2,5-halomethylfurans provided interesting products as alternatives to the normally anticipated Michaelis-Becker substitution-type products.452 Rather than simple substitution, overall reduction of the halomethyl linkage(s) to methyl(s) were observed with a Michael-type addition of phosphorus to the 4-position of the ring. 

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