METHOD FOR PREPARING PHOSPHONOFORMIC ACID TRISODIUM SALT HEXAHYDRATE Russian patent published in 2004 - IPC

FIELD: chemistry of organophosphorus compounds, chemical technology. SUBSTANCE: invention relates to the improved method for preparing phosphonoformic acid trisodium salt hexahydrate. Method is carried out by silylation reaction of phosphorous acid with hexamethyldisiloxane taken in 1.5-2.5-fold excess of stoichiometric amount that is necessary for monosilylation. The following silylation and alkylation of intermediate products of reaction are carried out by simultaneous addition of hexamethyldisilazane to reaction mass in the amount 75-95% of stoichiometric necessary amount and alkylchloroformate. Saponification of phosphonoformic acid triester is carried out for two stages where at the first stage 20-70% of stoichiometric necessary alkali is used and the remained amount of alkali is used at the second stage. Phosphonoformic acid trisodium salt hexahydrate elicits an antiviral effect and used in medicine. Invention provides increasing the end product yield and purity degree corresponding to requirements of The State Pharmacy Committee making demands for substances for injection solutions. EFFECT: improved preparing method, valuable medicinal properties of compound. 2 ex