Diphosphonic acid esters

Tavs, P, Synthesis of fra i-ethylene-l,2-diphosphonic acid esters and conversion into cyclohexane-1.2-diphosphonic acid, Chem. Ber., 100, 1571, 1967. 

R = Et), but cw-l,2-dichloroethene fails to react. Evidently, and by complete contrast, a 1 1 mixture of cis- and trans-l,2-dihromoethenQ affords only trans-(l,2 ethenediyl)diphosphonic acid ester 1,1,2-Trichloroethene suffers dechlorination at some stage in its reaction with triethyl phosphite the products are the esters 218 (R = Et) and 219 (R = Et), in approximately 2 1 ratio. ... 

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). 

Leroux, Y, El Manouni, D., Safsaf, A., Neuman, A., Gillier, H., and Burgada, R., Structural smdy of l-hydroxyethane-l,l -diphosphonic acid tetramethyl ester and of l-hydroxy-l-phenyhnethane-l, -diphosphonic acid tetramethyl ester. Phosphorus, Sulfur Silicon Relat. Elem., 56, 95, 1991. 

Tetraethyl Ester Diphosphonic Acid A200 Industrial 152... 

A particularly important example of a gem-diphosphonic acid is, in fact, the simplest, namely methylenebisphosphonic acid (39) n- 1). The interaction of diiodomethane with excess triisopropyl phosphite at 150-160 °C has provided 50-60% of tetraisopropyl meth-ylenebisphosphonate , but marginally better yields are reported to be obtainable if dibro-momethane is employed Lower yields of the tetraethyl ester are obtainable using triethyl phosphite, and it should also be noted that a difference in the ratio of reactants is liable to provide dialkyl (halomethyl)phosphonates (Chapter 3, Section II. A). A similar procedure has provided the tetraethyl esters of a,co-alkanebisphosphonic acids (39) n - l-10) In a like manner, Dahl and Block " have obtained methylenebisphenylbisphosphinic acid (40) via its diisopropyl ester (not isolated) from diiodomethane and diisopropyl phenylphos-phonite. 

Unexpectedly, esters of buta-1,3-dienyl-2,3-diphosphonic acid add diethylamine across only one of the C=C bonds Amines add to phosphorylated quinonemethides as indicated to give the a-aminobenzylic phosphonic diesters 293". ... 

Organic phosphorus-containing compounds (mono and dialkyl esters(C2 — Cio) of phosphoric acid, hydroxyethylidene-diphosphonic acid, nitrile-tris (methylene phosphonic acid) are mainly used as ingredients of polymer coatings. They are related to Cl of the anodic-passivating type [63]. 

Isobutylene is eliminated when t-butylaminomethylphosphonic acid, Bu NHCH2P(0)(0H)2, is heated in a sealed tube with concentrated hydrochloric acid, giving a high yield of aminomethylphosphonic acid, H2NCH2P(0)(0H)2 a similar reaction with simultaneous ester hydrolysis occurs with Bu N[CH2P(0)(0Et)2]2, providing an easy route to imino-dimethylene diphosphonic acid. ... 

Pyrophosphorous acid (diphosphorous acid, diphosphonic acid), H4P2O5, is tautomeric. Inorganic salts exist in the phosphonate form (5.232b), but esters in the phosphite form (5.232a) are known (Chapter 6.18), as well as fluoro derivatives (4.234). 

The tetraethyl ester of 1,1-vinylidenediphosphonic acid has been used to make cross-linked copolymers which are ion-exchange resins with selective chelation properties for toxic metal cations (78). An alternative method for introducing the diphosphonic acid structure is by reaction of a methylenediphosphonic ester with chloromethylated styrene copolymer beads (79). At least one such resin class, Diphonix, also containing sulfonic acid and other functional groups, has shown promise for treatment of radioactive waste and for iron control in copper electrowinning (80,81). 

Diphosphonic acids and esters Pyrophosphonic acids and esters 20... 

Maier, L., Organic phosphorus compounds. Part 58. Preparation and properties of acetylene diphos-phonates, haloethene-l,2-diphosphonates, and the corresponding acids. Phosphorus, 2, 229, 1973. Garibina, V.A., Dogadina, A.V., Zakharov, V.I., lonin, B.I., and Petrov, A.A., (Haloethynyl)phospho-nates. Synthesis and electrophihc reactions of (chloroethynyl)phosphonic esters, Zh. Obshch. Khim., 49, 1964, 1979 J. Gen. Chem. USSR (Engl. Transl.), 49, 1728, 1979. 

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). 

Esters of pyrophosphoric acid (Table 5.27) are also efficient complexing agents as well as dial-kylamino derivatives such as HMPA and OMPA (Chapter 7) and diphosphonates (Chapter 6.18). Typical complexes formed by tributyl phosphate (TBP) are... 

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