Hoechst Aktiengesellschaft

Udo Dettmeier

Ernst I Leupold

Hans-Jerg Kleiner

Klaus Gehrmann

Alexander Ohorodnik

Knut Riedel

Walter Reimann

Georg Weichselbaumer

Marita Neuber

Guenter Roscher

Manfred Kauffelt

Willi Herzog

Gustav Gimpel

Heinz-Josef Berns

Eduard Zeisberger

The invention relates to a process for preparing dimethyl vinylphosphonate by thermal dissociation of dimethyl 2-acetoxyethanephosphonate in the gas phase, which comprises vaporizing dimethyl 2-acetoxyethanephosphonate and dissociating it without catalysis at a temperature of from 400.degree. to 700.degree. C. into dimethyl vinylphosphonate and acetic acid.

Process for preparing dimethyl vinylphosphonate from dimethyl

Process for the preparation of monoisopropylnaphthalene by alkylation of naphthalene with the aid of zeolites of the faujasite type as catalysts, wherein the cations of the zeolites have been replaced by alkaline earth metal ions.

Process for the preparation of monoisopropylnaphthalene

Process for the purification of organic compounds contaminated by dissolved metal compounds. The present invention relates to a process for the purification of organic compounds contaminated by dissolved metal compounds, by bringing the contaminated organic compound into contact with an ion exchanger resin, the functional group of which contains both a secondary amine group and a phosphonate salt radical and/or a phosphonic acid radical.

Process for the purification of organic compounds contaminated by

The process for separating off rare metal catalysts used in the preparation of ether-carboxylic acids by catalytic oxidation with a suspended catalyst comprises carrying out a crossflow filtration and pretreating the filter elements used with a medium which is not solid under the treatment conditions and is composed of one or more carboxylic acids.

Process for separating catalysts from suspensions by filtration

Production of 2-chlorobutadiene-(1,3) by the dehydrochlorination of 3,4-dichlorobutene-(1) in an aqueous solution of an alkali metal or alkaline earth metal hydroxide in the presence of an alcohol having between 2 and 4 carbon atoms at elevated temperature, and distilling off resulting 2-chlorobutadiene-(1,3). To this end, a reaction zone is continuously supplied with 3,4-dichlorobutene-(1), an alcohol and the aqueous hydroxide solution and the whole is heated to boiling therein while passing a stream of inert gas therethrough; resulting 2-chlorobutadiene-(1,3) is distilled off from the reaction zone and fractionated until pure; a reaction mixture which commences to separate into two layers comprising an upper layer and a lower layer is retained in the reaction zone; aqueous alcohol in excess is continuously removed from said upper layer through an overflow and the alcohol is recovered; the lower layer consisting of an aqueous/alkaline solution of unreacted hydroxide, chloride salt and minor amounts of alcohol is continuously removed through the bottom of the reaction zone; the lower layer is distilled so as to concentrate it; precipitated chloride salt is isolated, and concentrated liquor is recovered.

Production of 2-chlorobutadiene-1,3

Novel tertiary phosphine oxides containing in one radical at least two hydroxy groups or functional derivatives thereof are obtained by adding olefins having at least two hydroxy groups or functional derivatives thereof to secondary phosphine oxides at elevated temperatures in the presence of a free radical generator. The products are useful as flame-retardant agents and intermediates for anti-corrosive agents and pesticides.

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Kelkheim, Germany

Udo Dettmeier