| Synthesis | In industry, glacial acetic acid and phosphoryl trichloride are usually used, and then the acylation product and phosphorous trichloride hydrolyzate are condensed. Add the metered amount of water and glacial acetic acid into the reaction kettle and stir evenly. Phosphorus trichloride was added dropwise under cooling, and the reaction temperature was controlled at 40-80°C. The reaction by-product hydrogen chloride gas is condensed and sent to the absorption tower to recover hydrochloric acid. The overflowed acetyl chloride and acetic acid were condensed and returned to the reactor. After dropping phosphorus trichloride, the temperature was raised to 100-130°C, and refluxed for 4-5h. After the reaction, hydrolyzed with steam to evaporate the residual acetic acid and low boilers to obtain 1-Hydroxyethylidene-1,1-diphosphonic acid. |
| Description | Hydroxyethylidene diphosphonic acid (HEDP) is a new type of chlorine-free electroplating complexing agent. It is used as the main agent for stable water quality in the circulating cooling water system, and plays the role of corrosion and scale inhibition. This product is one of the organic polyphosphonic acid-free water tablet conditioners. There are also some other varieties of such products produced in China, such as aminotrimethylenephosphonic acid (ATMP): [CH2PO(OH)2]3N and ethyl acetate Diaminetetramethylenephosphoric acid (EDTMP) and so on. Organic polyphosphonic acid is a type of water treatment agent developed in the late 1960s and confirmed around the 1970s. |
| Chemical Properties | light beige powder |
| Originator | Etidron,Gentili,Italy,1977 |
| Uses | 1-Hydroxyethylidenebis(phosphonic acid) acts as human protein tyrosine phosphatase inhibitor. It is also useful for photographic applications. It finds application to strengthen bone, osteoporosis treatment and to treat Paget's disease of bone. In addition, it is used in corrosion inhibition in circulating cool water systems, oil fields and low-pressure boilers with electric power, the chemical industry, metallurgy and fertilizers. It is also utilized for formulating reverse osmosis and thermal desalination anti-scaling agents. Furthermore, it is used in detergents, water treatment, cosmetics and pharmaceuticals. |
| Uses | Etidronate (Didronel) is a human protein tyrosine phosphatase inhibitor with IC50 of 0.2 μM. |
| Definition | ChEBI: A 1,1-bis(phosphonic acid) that is (ethane-1,1-diyl)bis(phosphonic acid) having a hydroxy substituent at the 1-position. It inhibits the formation, growth, and dissolution of hydroxyapatite crystals by chemisorption to calcium phosphate surfaces. |
| Manufacturing Process | Phosphorous acid was premixed with acetic acid to form a 50 wt % solution ofphosphorous acid dissolved in acetic acid. The acids were mixed on a molarbasis of 1.36:1, acetic acid to phosphorous acid, and this corresponded on amol percentage basis to 57.6% acetic acid and 42.4% phosphorous acid.Acetic anhydride was continuously metered into a stream of the phosphorousacid-acetic acid mixture to form the reaction solution. The acetic anhydridewas metered into the acid mixture at a mol ratio of 1.33 mols of aceticanhydride per mol of phosphorous acid. The metering rates were 18.5 lb/hr ofthe phosphorous acid/acetic acid premixed solution and 15.1 lb/hr aceticanhydride. The reaction solution was continuously passed through a heatexchanger where it was heated to 190°F then it was continuously fed into atwo stage back-mix reaction zone where due to the heat of reaction thetemperature rose to 275°F. The average residence in the reaction zone was 27min. The reaction zone consisted of two back-mix reactors each having acapacity of 7.5 pounds of the reaction solution. A stream of reaction solutionwas continuously with drawn from the second reactor and continuously mixedwith a stream of water which was being metered at a rate of 2 lb/hr. Thisamount of water corresponded to 18% excess over the theoretical amountnecessary to hydrolyze all of the acetyl-containing compounds in the reactionsolution to free acids. The hydrolyzed solution was continuously passedthrough a heat exchanger and cooled to room temperature after which thesolution was continuously passed to a crystallizer where, with agitation, theethane-1-hydroxy-1,1-diphosphonic acid crystallized. The slurry was thenfiltered and the crystals were recovered and dried. Analysis of the productshowed a conversion rate of phosphorous acid to ethane-1-hydroxy-1,1-diphosphonic acid of 86%. Sodium hydroxide may be used to give thedisodium salt. |
| Brand name | Didronel (Millot Laboratories, France);Didronel (Procter & Gamble). |
| Therapeutic Function | Bone calcium regulator |
| Flammability and Explosibility | Not classified |
| in vitro | Etidronic acid (Etidronate) (10 mM, 24 h) shows cytotoxicity, causes a decrease in the S-phase population and an increase in the G2/M population, and induces p53 mutation in MCF-7 cells.
Etidronic acid (100 nM, 24 h) induces osteoclast apoptosis, which displays characteristics of apoptosis, including chromatin condensation and changed cellular and nuclear morphology, detected by fluorescence microscopy. |
