METHOD FOR PRODUCING BIS(3-AMINOPHENYL)PHOSPHENIC ACID TRIETHYLAMMONIUM SALT Russian patent published in 2018 - IPC C07F9/30 

FIELD: chemistry.

SUBSTANCE: invention relates to a process for the preparation of bis (3-aminophenyl)phosphinic acid triethylammonium salt, which can be used to produce polyimide materials having high mechanical strength in combination with chemical and thermal stability, used, for example, in the production of fuel cell membranes. Proposed method comprises the step of forming an intermediate product – bis(3-aminophenyl)phosphinic acid, which is carried out by adding an aqueous solution of sodium hydroxide to the aqueous solution of bis(3-ammoniophenyl)phosphinic acid dichloride, dropwise while vigorous mixing and at room temperature until pH 4.6–5.0 or to an ethanol solution of bis(3-ammoniophenyl)phosphinic acid dichloride, a 5–50 fold molar excess of 1,2-propylene oxide is added dropwise while vigorous mixing and at room temperature until chloride ions disappear in the reaction mass, after which the reaction mixture is mixed at room temperature until the precipitation of bis(3-aminophenyl)phosphinic acid, an organic solvent (ethanol or ethyl acetate) is added to the isolated acid and triethylamine is added dropwise, reaction mixture is mixed at room temperature and bis(3-aminophenyl)phosphinic acid triethylammonium salt is isolated therefrom, which is purified by recrystallization from acetonitrile.

EFFECT: new effective methods for the preparation of bis(3-aminophenyl)phosphinic acid triethylammonium salt are proposed.

7 cl, 6 ex