Bayer Aktiengesellschaft

Christoph Holzner

Hans-Dieter Block

Hans-Heinrich Moretto

Wolfgang Ohlendorf

Ottfried Schlak

Roland Kleinstuck

Karl-Heinz Mitschke

Dietrich Pantke

Armin Spaniol

Hans Dahmen

Alfred Wagner

Rosemarie Grizan

Johannes Jezierski

The present invention relates to phosphorus-containing compounds based on 1-hydroxypropane-1,3-diphosphonic acid and to the acid itself of general formula (I) ##STR1## in which M.sup.1, M.sup.2, M.sup.3, M.sup.4 and M.sup.5, independently of one another, each denote a radical from the series hydrogen, alkali metal, an equivalent of ammonium, alkyl- or hydroxyalkyl-substituted ammonium, a process for the preparation thereof, novel intermediates and the use thereof as a corrosion inhibitor, scale inhibitor and as a flame retardant.

Phosphorus-containing compounds based on 1-hydroxypropane-1,

The present invention relates to a process for the preparation of symmetrically substituted phosphoric acid diesters of long-chain linear or branched alcohols of chain length C.sub.4 to C.sub.22.

Dialkylphosphoric acids by the methanol method

Use of diethyl dodecylphosphonate (DEDP) for the extraction of acids and metal salts from aqueous solutions.

Extraction of acids and metal salts from aqueous solutions with diethyl

Preparing O,O'-diesters of thiophosphoric acid, O-monoesters of thiophosphonic acid or thiophosphinic acids and their salts, from diesters of phosphorous acid, monoesters of phosphorous acids or phosphinous acids and sulphur in the presence of an aqueous solution of an auxiliary base. The solutions can be used in further syntheses or as extraction agent for cations.

Synthesis of an O,O' -diesters of thiophosphoric acid, an O-ester of

This invention relates to an improved process for the production of 2-phosphono-butane-1,2,4-tricarboxylic acid (PBTC) and the alkali metal salts thereof, in which process dialkyl phosphite, preferably dimethyl or diethyl phosphite, and ethene-1,2-dicarboxylic acid dialkyl ester, in particular the dimethyl or diethyl ester of maleic acid and/or fumaric acid, are initially reacted in the presence of a basic catalyst to yield a phosphonosuccinic acid tetraalkyl ester, the resultant ester is thereupon reacted without further working up with acrylic acid alkyl ester, preferably methyl or ethyl acrylate, in the presence of an alkaline catalyst and the reaction product obtained in this manner is saponified without further working up to yield PBTC or the alkali metal salts thereof. The product when mixed with bleaching lye exhibits reduced chlorine depletion.

Production of 2-phosphonobutane-1,2,4-tricarboxylic acid and the alkali

In the preparation of dimethylamine-borane by reacting an alkali metal or alkaline earth metal borohydride with a dimethylammonium salt, the improvement which comprises effecting the reaction in a liquid mixture comprising dimethylamine as a solvent and an additional organic solvent.

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Koln, Germany

Christoph Holzner