Abstract: The present invention is related to a method for the synthesis of ethane-1-hydroxy-1,1-diphosphonic acid or its salt which includes the steps of reacting tetraphosphorus hexaoxide and acetic acid under controlled reaction conditions; hydrolyzing the formed ethane-1-hydroxy-1,1-diphosphonic acid condensates to form ethane-1-hydroxy-1,1-diphosphonic acid; further processing the ethane-1-hydroxy-1,1-diphosphonic acid solution. The process according to the method of the present invention is highly controllable and further is characterized by a high selectivity.

Abstract: A method for the synthesis of a heterocyclic hydrogen phosphine oxide, having the general formula: wherein: R is a aliphatic or aromatic divalent group optionally including one or more heteroatoms and optionally having one or more substituents and X and Y are independently selected from —O—, —C(O)O— and —NR?— wherein R? is a monovalent group optionally having one or more heteroatoms including the steps of: a) forming a reaction mixture by mixing a compound having the general formula HX—R—YH and tetraphosphorus hexaoxide; and b) recovering the resulting compound comprising the heterocyclic hydrogen phosphine oxide.

Abstract: A method for the synthesis of N-(phosphonomethyl)glycine or one of its derivatives selected from the group consisting of its salts, its phosphonate esters, or its phosphonate ester salts, which includes the steps of: a) forming, in the presence an acid catalyst, a reaction mixture having 2,5-diketopiperazine, formaldehyde and a compound including one or more P-0-P anhydride moieties, the moieties having one P atom at the oxidation state (+III) and the other P atom at the oxidation state (+III) or (+V), to form N,N?-bisphosphonomethyl-2,5-diketopiperazine, its mono- to tetra phosphonate esters, the dehydrated forms of N,N?-bisphosphonomethyl-2,5-diketopiperazine and the phosphonate esters of its dehydrated forms; and b) hydrolyzing the N,N?-bisphosphonomethyl-2,5-diketopiperazine, its dehydrated forms or their phosphonate esters to obtain N-(phosphonomethyl)glycine or one of its derivatives selected from the group consisting of its salts, its phosphonate esters and its phosphonate ester salts.

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 synthesis of N-(phosphonomethyl) glycine or one of its derivatives selected from the group of its salts, its phosphonate esters and its phosphonate ester salts, including the steps of: a) forming a reaction mixture having an acid catalyst, N,N?-bis(carboxymethyl)-2,5-diketopiperazine and a compound having one or more P—O—P anhydride moieties, wherein the moieties have one P atom at the oxidation state (+III) and the other P atom at the oxidation state (+III) or (+V), to form N,N?-bis(phosphonomethyl)-2,5-diketopiperazine, its dehydrated forms or their phosphonate esters; b) hydrolyzing the reaction mixture to form N-(phosphonomethyl)glycine or one of its derivatives selected from the group consisting of its salts, its phosphonate esters and its phosphonate ester salts.

Abstract: The present invention is related to a new method for the synthesis of N-(phosphonomethyl)glycine or one of its derivatives selected from the group consisting of its salts, its phosphonate esters and its phosphonate ester salts, comprising the steps of: a) forming a reaction mixture comprising an acid catalyst, N,N?-bis(carboxymethyl)-2,5-diketopiperazine and a compound comprising one or more P—O—P anhydride moieties, wherein said moieties comprise one P atom at the oxidation state (+111) and the other P atom at the oxidation state (+111) or (+V), to form N,N?-bis(phosphonomethyl)-2,5-diketopiperazine, its dehydrated forms or their phosphonate esters; b) hydrolyzing the reaction mixture to form N-(phosphonomethyl)glycine or one of its derivatives selected from the group consisting of its salts, its phosphonate esters and its phosphonate ester salts.

Abstract: A method for the manufacture of amino alkylene phosphonic acids is disclosed. Pure P4O6 is hydrolyzed in the presence of a homogeneous Broensted acid catalyst whereby the pH of the reaction medium is maintained below 5 and the free water content of said reaction medium is, after the P4O6 hydrolysis has been completed, from 0 to 40%. The required amine component can be added before, during, or in one preferred execution, after the P4O6 hydrolysis has been completed. Formaldehyde is then added and the reaction mixture containing the P4O6 hydrolysate, the amine and the formaldehyde is reacted in presence of a Broensted acid catalyst selected from homogeneous and heterogeneous species. The amino alkylene phosphonic acid reaction product can then be recovered in a manner known per sé.

Abstract: A process for the manufacture of dialkyl phosphites is disclosed. In detail, dialkyl phosphites are prepared starting from P4O6, or partially hydrated species thereof cumulatively P—O, by reacting specific molar ratios of alcohol and P—O, containing from 1 to 6 P—O—P bonds in the molecule, in the presence of trialkylphospite (TAP) to thus yield high purity and high yield of dialkyl phosphites. The P—O reactant is preferably represented by liquid P4O6.

Abstract: A method for the manufacture of dialkyl phosphites is disclosed wherein a P—O component containing from 1 to 6 P—O—P bonds in the molecule is reacted with an alcohol and a carboxylic acid ester having from 1 to 6 carbon atoms in the alkyl group and from 5 to 20 carbon atoms in the esterifying alkyl group of the ester. The dialkyl phosphites are formed under simultaneous removal by distillation of the carboxylic acid formed.

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 concentrated phosphorous acid starting from pure P4O6 is disclosed. The P4O6 is hydrolyzed, preferably under stirring in water in the presence of a homogeneous Broensted acid catalyst while maintaining in the hydrolysis/reaction medium a pH below 5 whereby the free water level, at the completion of the hydrolysis, is in the range from 0 to 40%.

Abstract: A process for the production of a reaction product consisting essentially of P4O6 is carried out by reacting oxygen with phosphorus in an exothermic reaction in a reaction unit. Heat created by the exothermic reaction is removed by feeding P4O6 and/or by-products of the process into the reaction unit. The generated reaction product is then quenched to a lower temperature where no essential decomposition of the reaction product occurs, and at least part of P4O6 is separated from the reaction product obtained after quenching. The resulting yield of P4O6 based on the phosphorus used is improved and the heat of the exothermic reaction can be controlled in an economic way.

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 invention relates to a process for the production of P4O6 of high purity by reacting oxygen, or a mixture of oxygen and an inert gas, with gaseous or liquid phosphorus to generate said reaction product in a reaction unit. The reaction product is kept in the reaction unit at an average temperature in the range of 1600 and 2000 K by removing the heat created by the exothermic reaction of phosphorus and oxygen. A residence time of at least 1 second of the reaction product passing the reaction unit is maintained. The reaction product is then conventionally cooled in a quenching unit connected with the reaction unit. The final reaction product contains P4O6 with a very low content of elemental phosphorus.

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 is disclosed wherein a P—O component containing from 1 to 6 P—O—P bonds in the molecule is reacted with an alcohol and a carboxylic acid ester having from 1 to 6 carbon atoms in the alkyl group and from 5 to 20 carbon atoms in the esterifying alkyl group of the ester. The dialkyl phosphites are formed under simultaneous removal by distillation of the carboxylic acid formed.

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.