Abstract: An improved method for the manufacture of phosphonoalkyl iminodiacetic acid M2PO3—X—N—(CH2COOM)2 wherein X is a C1-6 linear or branched alkyl group; and M is selected from hydrogen, alkali, earth-alkali, ammonium and protonated amine is disclosed. The iminodiacetic acid starting material is reacted with a substantially stoichiometric amount of phosphorous acid, in the presence of a large excess of phosphoric acid to thereby yield a reaction medium insoluble reaction product (PAI-DA) which can be separated from the reaction medium. In a particularly preferred approach, the phosphorous acid is prepared in situ starting from liquid P4O6.

Abstract: The technology of this invention concerns a method for the manufacture of hydroxy diphosphonic acids containing an amino moiety. The method specifically involves reacting a liquid P4O6 with an aminocarboxylic acid in the presence of a sulfonic acid. The aminocarboxylic acid is selected from 3 structurally different compounds. The amino hydroxy diphosphonic acids can be synthesized with high selectivity and purity and the unreacted starting raw materials can easily and conveniently be recirculated.

Abstract: An improved method for the manufacture of phosphonoalkyl iminodiacetic acid M2PO3—X—N—(CH2COOM)2 wherein X is a C1-6 linear or branched alkyl group; and M is selected from hydrogen, alkali, earth-alkali, ammonium and protonated amine is disclosed. The iminodiacetic acid starting material is reacted with a substantially stoichiometric amount of phosphorous acid, in the presence of a large excess of phosphoric acid to thereby yield a reaction medium insoluble reaction product (PAI-DA) which can be separated from the reaction medium. In a particularly preferred approach, the phosphorous acid is prepared in situ starting from liquid P4O6.

Abstract: A method for the manufacture of aminopolyalkylene phosphonic acid of a specific general formula is described. In particular, a mixture of specifically defined ranges of reactants to wit: phosphorous acid; an amine; formaldehyde and an aminopolyalkylene phosphonic acid, having the same general formula as the compound to be manufactured, are reacted to thus yield a product of outstanding selectivity and purity with substantially reduced levels of non-desirable by-products.

Abstract: The technology of this invention concerns a method for the manufacture of hydroxy diphosphonic acids containing an amino moiety. The method specifically involves reacting a liquid P4O6 with an aminocarboxylic acid in the presence of a sulfonic acid. The aminocarboxylic acid is selected from 3 structurally different compounds. The amino hydroxy diphosphonic acids can be synthesized with high selectivity and purity and the unreacted starting raw materials can easily and conveniently be recirculated.

Abstract: A method for the manufacture of dialkyl phosphites by reacting a P—O component containing from 1 to 6 P—O—P bonds in the molecule, with an alcohol and a ketal corresponding to a selected formula, said ketal will not lead to the formation of an enol structure. The level of the ketal is expressed in relation to the level of co-reactants. A preferred ketal is void of any carbon-hydrogen bonds on the ?-carbon atom in the ketal structure.

Abstract: A method for the manufacture of aminoalkylene phosphonic acids broadly is disclosed. In the essence, an amine corresponding to a specific formula is reacted in aqueous medium with phosphorous acid and formaldehyde to thereby yield a medium insoluble reaction product. The insoluble product formed i.e. the aminoalkylene phosphonic acid can be separated, optionally washed, and recovered. This process yields high purity and selectivity reaction products. The excess phosphonic acid can be recycled into the processing sequence.

Abstract: An improved method for the manufacture of phosphonoalkyl iminodiacetic acid (PAIDA) is disclosed. The iminodiacetic acid starting material is reacted with a considerable amount, in excess of stoichiometric requirements, of phosphorous acid to thereby yield a reaction medium insoluble reaction product which can be separated from the reaction medium. In a particularly preferred approach, the phosphorous acid is prepared in situ starting from liquid P4O6.