Phosphorous acid dialkyl phosphites

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)... 

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). 

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]. 

Bonds to Oxygen.—Compounds of Lower Oxidation State. Mixed sulphur-phosphorus anhydrides result when sulphonic acids and dialkyl hydrogen phosphites react according to equation (17).448 Further work on the preparation of trimethylsilyl esters of phosphorous acids has been carried out by... 

Pudovik, A.N., Moshkina, T.M., and Konovalova, I.V., New method of synthesis of esters of phosphonic and thiophosphonic acids. Part 31. Addition of phosphorous and hypophosphorous acids, dialkyl hydrogen phosphites, and esters of phosphonoacetic acid to esters of maleic acid, Zh. Obshch. Khim., 29, 3338, 1959 Chem. Abstr, 54, 152231, 1960. 

Optically active phosphorus(iii) acid esters PhR P (OR ) have recently been prepared for the first time by the reaction of a chiral phosphorus chloride and an alcohol or thiol in the presence of an optically active amine, in this case (-)-NN-dimethyl-(l-phenylethyl)amine. (See also Refs. 449 and 450). A kinetic investigation shows that phosphorous acid and chloral react to give 2,2,2-trichloro-l-hydroxyethyl phosphonate at a much lower rate than the corresponding reaction with dimethyl hydrogen phosphite. Phosphorus trichloride and dialkyl phosphites (R0)2P(0)H have been shown to react at low temperature in the presence of pyridine, producing tris(dialkoxyphosphoryl)phosphines [(RO)2P(0)]3P. ... 

Synthesis of Phosphoric Acids and their Derivatives.-New approaches to the preparation of dialkyl phosphorofluoridates include the treatment of a vinyl phosphate, e.g.,(l), or an irninophosphace, e.g.,(2), with triethylamine tris(hydrogen fluoride) when the alkyl group consists of a suitably protected nucleoside, the reaction between mono(crimethylsilyl) phosphite in pyridine and sulphuryl chloride fluoride at -30° has been successfully explored. Dibenzyl phosphorofluorldate, hitherto unreported, has been obtained from tecrabenzyl diphosphate and caesium fluoride, and also from the reaction between dibenzyl hydrogen phosphate and 2-fluoro-N-methylpyridinlum tosylate. ... 

Dialkyl phosphites react with (hydroxymethyl)amines, giving a-amino phosphonic esters the same products can often be obtained by reaction of the phosphite with aminals, Schiff bases, or an aldehyde plus an amine321 (cf. page 708). Free phosphorous acid can itself be a-aminoalkylated in an acid medium, when according to the amine selected (ammonia can also be used) up to three methylenephosphonic acid groups can be attached to one nitrogen atom 322... 

Phosphorous acid, H3PO3, is generated by hydrolysis of PCI3 - industrially this is carried out by spraying the chloride into steam at 190 °C. Esters of the acid, both the trialkyl esters [P(OR)3] and the dialkyl esters [(R0)2P(0)H], can be produced directly by substituting the appropriate acid for the water. The esters find much use thus, triphenyl phosphite is most widely used in the manufacture of polyvinyl chloride, while trinonylphenyl phosphite is an excellent stabilizer for the same polymer. 

Titanium tetrachloride is an efficient reagent for the conversion of trialkyl phosphites and dialkyl hydrogen phosphonates into dialkyl phosphorochloridates. Imidazolides and dialkyl or diaryl phosphoric acids react with acyl fluorides - benzoyl fluoride and oxalyl difluoride being the reagents of choice - to give quantitative yields of the phosphoryl fluorides. The procedure is adaptable to the preparation of fluorides of carbohydrate phosphates in this field, the reaction between the ceu bohydrate and tris-l//-imidazolylphosphine oxide or sulphide with the replacement of one imidazole... 

The asymmetric hydrophosphonylation reaction of aldimines (207) with dialkyl phosphites (206) has been reported using catalytical amounts of the phosphoric acid (125), derived from (7 )-BINOL to afford (l )-amino phos-phonates (208) in good to high enantioselectivities (up to 90% cc) (Scheme 58). ... 

Phosphoric acid, triphenyl ester. See Triphenyl phosphate Phosphoric acid, tris (2-ethylhexyl) ester. See Trioctyl phosphate Phosphoric acid, tris (methylphenyl) ester Phosphoric acid, tritolyl ester. See Tricresyl phosphate Phosphoric acid, zinc salt (2 3). See Zinc phosphate Phosphorodithioic acid, mixed 0,0-bis (iso-butyl and pentyl) esters, zinc salt. See Zinc dialkyl dithiophosphate Phosphorous acid, cyclic neopentanetetrayl bis (2,4-di-t-butylphenyl) ester. See Bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite Phosphorous acid, triisooctyl ester. See Triisooctyl phosphite Phosphorous acid triphenyl ester. See Triphenyl phosphite... 

Depending on the temperature conditions, carbon disulfide can be phosphorylated by sodium dialkyl phosphites either at the carbon or at one of the sulfur atoms. At relatively low temperatures (2-8 °C), the phosphorus-containing xanthate I is obtained [375], whereas at higher temperatures (70-100 °C), the 0,0-diethyl ester of S-thioacetyl-thio-phosphoric acid II is the major product [376]. 

Dialkyl phosphites are prepared from phosphorous acid and trialkyl phosphites. 

Sodium hydroxide/carbon tetrachloride/ tetra-n-butylammonium bromide Phosphoric acid esters from dialkyl phosphites... 

Mixed phosphoric acid esters from dialkyl phosphites (RO)2POH - (RO)2POOR s. 10,107si7 mixed polyfluoroalkyl phosphates with [PhCH2NEt3] Cr as catalyst cf. B.M. Adamov et al., Zh. Obshch. Khim. 58, 2774-80 (1988) dialkyl aryl phosphates from dicyclohexylammonium aroxides s. Purnanand et al.. Tetrahedron Letters 30, 1687-8 (1989). 

Na added to a soln. of diethyl thionophosphite in benzene, a soln. of benzo-phenone in benzene added dropwise after the Na has dissolved, and stirred several hrs. at room temp. diethyl S-diphenylmethyl monothiolphosphate. Y 85%. F. e. and procedures, also phosphoric acid esters from dialkyl phosphites and ketones, s. H. Timmler and J. Kurz, B. 104, 3740 (1971). 

Dialkyl from trialkyl phosphites and phosphorous acid Reactions of dialkyl phosphites... 

A one-pot process has been devised for the synthesis of dialkyl [(a-phenylamino)ben-zyljphosphonates from dialkyl hydrogenphosphonate, benzaldehyde and aniline, presumably adaptable for other aromatic amines or aldehydes To avoid multiple reactions of the Mannich type when using a primary amine and a particularly reactive carbonyl component such as formaldehyde, initial silylation of the amine, or the use of diethyl trimethylsilyl phosphite, are valuable moderating variations The amine can be replaced by a carboxamide" or carbamate ester, conveniently the benzyl ester , and the product can then be selectively deacylated with HBr in acetic acid at room temperature or by hydrogenolysis. Alternatively, even a phosphoric amide may be used to afford an A-phos-phorylated product (221)" ... 

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