Phosphites, dialkyl

Phosphoms trichloride may also be used directly ia the production of trialkyl phosphites, dialkyl phosphonates, and dialkyl alkylphosphonates ... 

The kinetics of the reaction of trialkyl phosphites, dialkyl aryl-phosphonites, alkyl diarylphosphinites, and triarylphosphines with Sg has been studied the effects of structural changes on the rate (Ph2POR > PhP(OR>2 > P(OR)g > Ph P) and on the Hammett p values are interpreted with respect to the mechanism. A general method to displace mercapto groups from carbon with clean inversion includes... 

Trialkyl phosphites, dialkyl alkylphosphonites, and alkyl dialkylphosphinites... 

Pudovik, A.N., and Khlyupina, N.L, New method of synthesis of esters of phosphonic and thiophos-phonic acids. Part 25. Addition of mixed dialkyl phosphites, dialkyl thiophosphites, and diallyl phosphite to unsaturated compounds, Zh. Obshch. Khim., 26, 1672, 1956 Chem. Abstr., 51, 3439f, 1957. 

Like dialkyl phosphites, dialkyl phosphinites R2PHO can be added under basic catalysis to, jS-unsaturated nitriles, esters, and amides.31... 

Mixed phosphites. Dialkyl phosphites HP(=0)(OR)2 are converted into mixed phosphites of the type (RO)jPOR by successive treatment with PhjP-DEAD and R OH, including phenol. 

With halogens, triaryl phosphites form phosphoranes which may dissociate into various aryloxy-phosphonium compounds. On the other hand, trialkyl phosphites undergo an Arbusov-type reaction with halogens (except F) at low temperature (6.349). Saturated carboxylic acids produce dialkyl phosphites (dialkyl esters of phosphonic acids), while unsaturated acids give dialkyl phosphonates (6.350, 6.351) and a-diketones give pentaoxyphosphoranes (6.344) above. Diphosphonates can be obtained from trialkyl phosphites (6.747). 

In the absence of a tertiary amine, the initial reaction is again the formatfon of a trialkyl phosphite and hydrogen chloride. The latter now reacts rapidly with the trialkyl phosphite to give the alkyl chloride and the dialkyl hydrogen... 

Triethyl phosphite is a colourless mobile liquid, insoluble in water. Trialkyl phosphites are valuable intermediates in the preparation of many organophosphorus compounds they readily form dialkyl esters of alkylphosphonic acids by the Arbusov reaction (p. 311). 

The unsuhstituted hydrogen atom of the dialkyl hydrogen phosphites can be readily replaced by chlorine, and thence by many other substituents including fluorine. 

If R = R, the reaction appears to be catalytic as a small quantity of R Cl will suffice to convert a considerable quantity of the trialkyl phosphite into the dialkyl alkylphosphonate (I). As little as o-i mol. of the alkyl iodide will suffice to isomerise the trialkyl phosphite. 

Dialkyl sulfates are esters of sulfuric acid tnalkyl phosphites are esters of phos phorous acid (H3PO3) and tnalkyl phosphates are esters of phosphoric acid (H3PO4)... 

Peroxide-decomposing antioxidants destroy hydroperoxides, the sources of free radicals in polymers. Phosphites and thioesters such as tris(nonylphenyl) phosphite, distearyl pentaerythritol diphosphite, and dialkyl thiodipropionates are examples of peroxide-decomposing antioxidants. 

Diall l Phosphite and Related Retardants. Pyrovatex CP is based on the reaction product of a dialkyl phosphite and acrylamide [79-06-17 the adduct is methylolated with formaldehyde [50-00-0] (66—68) ... 

Trialkyl esters of phosphonic acid exist ia two structurally isomeric forms. The trialkylphosphites, P(OR)2, are isomers of the more stable phosphonates, 0=PR(0R)2, and the former may be rearranged to resemble the latter with catalytic quantities of alkylating agent. The dialkyl alkylphosphonates are used as flame retardants, plasticizers, and iatermediates. The MichaeUs-Arbusov reaction may be used for a variety of compound types, including mono- and diphosphites having aryl as weU as alkyl substituents (22). Triaryl phosphites do not readily undergo the MichaeUs-Arbusov reaction, although there are a few special cases. 

Sulfites. The Hterature concerning dialkyl sulfites is extensive, although less than for sulfates. Reactions involving alkylation are similar to those of sulfates. Sulfites also undergo elimination, transesterification, and isomerization. The last two parallel reactions of phosphites. 

Dialkyl esters of 3,3 -thiodipropionic acid (53), cycHc phosphonites such as neopentylphenyl phosphite, derivatives of phosphaphenathrene-lO-oxide (54), secondary aromatic amines, eg, diphenylamine (55), and epoxidi2ed soybean oils (56) are effective stabili2ers for preventing discoloration of cellulose esters during thermal processing. 

ATHERTON TODD Phosphoramidate Synihasis Synthesis of phosphoramidates from formamides and dialkyl phosphite. 

Formation of esters of inorganic acids (Section 15.9) Alkyl nitrates, dialkyl sulfates, trialkyl phosphites, and trialkyl phosphates are examples of alkyl esters of inorganic acids. In some cases, these compounds are prepared by the direct reaction of an alcohol and the inorganic acid. 

Speziale and his co-workers have carried out comprehensive studies of the reactions of phosphorus compounds. It has been shown 108) that the reaction of N,N-dialkyl-a-trichloroacetamides (127) with phosphites and phosphines gives trichlorovinylamines (128). In general the trialkyl-phosphines gave somewhat higher yields (60 to 83%) and purer products... 

Dialkyl phosphites and phosphines have been shown to react with iminium salts. There are only a few examples of such reactions so that the generality has not yet been determined (44). 

Triethyl phosphite can be obtained from Virginia Carolina Chemical Corp., Eastman Kodak Co., Aldrich Chemical Co., K and K Laboratories, and Matheson, Coleman and Bell. The presence of dialkyl hydrogen phosphite or trialkyl phosphate is not deleterious, but a correction for assay is required. Fractionation readily separates triethyl phosphite (b.p. 48-49°/ll mm.) from diethyl hydrogen phosphite (b.p. 72°/ll mm.) and triethyl phosphate (b.p. 90°/10 mm.). The presence of amines and amine hydrochlorides may seriously interfere with the alkylation, especially in the case of trimethyl phosphite (see Table I). The checkers redistilled triethyl phosphite obtained from Matheson, Coleman and Bell. 

Dialkyl phosphites react with acyl halides such as lauroyl chloride to yield surface-active acid esters of acylphosphonic acid [84-87] see Eq. (40). 

Diesters of phosphorous acid are in general neutral because the phosphorous acid exists mostly in the phosphonate form with one hydrogen directly attached to the phosphorus. But with alkali metals the H can be changed against the alkali and reactive intermediates formed. Such alkali metal derivatives of dialkyl phosphites react with alkyl halides to give dialkyl alkanephosphonates, according to Eqs. (45) and (46). 

In a similar way, the preparation of alkylenediphosphonic acids occurs by using dialkyl phosphite with a,co-dichloralkanes in the presence of sodium see Eq. (48). 

In the alkyl chain hydroxy groups or side chains may be present. The reaction is somewhat different when acyl halides are used. Hydroxymethanediphosphonic acid is prepared by reacting phosgene with an alkali metal, dialkyl phosphite. The reaction is rapid and exothermic. The temperature is controlled between 10 and 20°C. After hydrolysis with HC1, hydroxymethanediphosphonic acid is recovered [91,92]. 

In the presence of strong alkali dialkyl phosphites can be added to unsaturated compounds. Thus salts of carboxyethyl- or dicarboxyethylphosphonic acid are obtained by addition of dialkyl phosphites to methyl acrylate [99] in the presence of sodium methylate in methanol. Diethylmaleate similarly gave diethyldiethylphosphonosuccinate [100], according to Eqs. (55) and (56) ... 

Reaction of Unsaturated Compounds with Dialkyl Phosphites The diesters of phosphorous acid are somewhat resistant to oxidation and used as intermediates for the reaction with olefins forming phosphonic acids. The reaction takes place in the presence of free radical initiators, such as di-/-bu-tyl peroxide [104,105]. 

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]. 

Dialkyl phosphites are added to unsaturated compounds in the presence of sodium ethylate or triethylamine forming, for instance, 2-(dialkylphosphono) propionic ester [152]. The same compounds are obtained by catalytic conversion of phosphites with propiolactones [153,154] see Eq. (85) ... 

The 9,10-phosphonostearic acid in form of its sodium salt shows a good thermal stability and was efficient as an inhibitor in rust protection. The diethyl-phosphonoacetoxystearic acid methyl ester is used as additive in high-pressure lubricants. Rust protection properties are also shown by 9,10-phosphonostearyl alcohol [157]. Trisodium 9,10-phosphonostearate possesses the best surface activity in an 0.2% aqueous solution showing 33 mN/m at 30°C and a pH value of 10.5 [156]. By the addition of dialkyl phosphite to a,p-unsaturated ketones the y-oxophosphonic acids are available [159]. Addition of dialkyl phosphite to y-ketoacids leads to a-hydroxy-y-carboxyphosphonates see Eq. (86) ... 

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