Abstract: .alpha.-(hydroxyimino)phosphonoacetic acids (also referred to as ".alpha.,.alpha.-disubstituted trifunctional oximes" and "Troika Acids") and their derivatives, and methods to prepare them are disclosed. Also disclosed are the structures and fragmentation pathways of the .alpha.-(hydroxyimino)phosphonoacetic acids. The .alpha.-(hydroxyimino)phosphonoacetic acids and derivatives are useful as pH sensitive chelating agents, enzyme activated drugs, drug delivery agents, phosphorylating reagents and photo-activated reagents.

Abstract: Methods for converting phosphonates into thiophosphonates and specific thiophosphonate compounds so produced are disclosed and claimed. The methods start with a reaction mixture formed of a phosphonate compound, including one or more strong electron-withdrawing groups located adjacent to the phosphorus in the compound, a slight excess of Lawesson's reagent, and a polar aprotic solvent. The reaction mixture is heated until reaction is complete and may be followed with separation or hydrolyzation steps to produce thiophosphonic acids and their addition salts. One of these thio-analogues, thiophosphonoformic acid (TPFA) is particularly effective at inhibiting HIV replication and in treating HIV infection.

Abstract: Methods for converting phosphonates into thiophosphonates and specific thiophosphonate compounds so produced are disclosed and claimed. The methods start with a reaction mixture formed of a phosphonate compound, including one or more strong electron-withdrawing groups located adjacent to the phosphorus in the compound, a slight excess of Lawesson's reagent, and a polar aprotic solvent. The reaction mixture is heated until reaction is complete and may be followed with separation or hydrolyzation steps to produce thiophosphonic acids and their addition salts. One of these thio-analogues, thiophosphonoformic acid (TPFA) is particularly effective at inhibiting HIV replication and in treating mammals infected with HIV.

Abstract: A method for the production of alpha-fluorinated methane diphosphonates consists of the reaction of diphosphonate esters with a strong base, preferably potassium t-butoxide, and perchloryl fluoride to produce alpha-mono and alpha,alpha-difluorinated derivatives which can be converted to the corresponding acids by mild hydrolysis. The synthesis of unsymmetrical alpha-fluorinated methanediphosphonate esters followed by selective hydrolysis produces unsymmetrical diesters of diphosphonic acids.