Hoechst Aktiengesellschaft

Hoechst Celanese Corporation

Adolf Schmidt

Siegbert Rittner

Hans Millauer

Edward G Zey

Leonhard Unverdorben

Siegfried Benninger

Rudolf Steiner

Uwe Stuven

Larry O Wheeler

Gary L Moss

2,7'-Dimethyl-1,1'-binaphthyl and a process for preparing 2,2'-dimethyl-1,1'-binaphthyl and 2,7'-dimethyl-1,1'-binaphthyl by electrochemically oxidatively dimerizing 2-methylnaphthalene in the presence of acetonitrile/water/electrolyte salt mixtures which additionally contain at least one further component which, is immiscible or only partially miscible with water, and rectifying the reaction mixture obtained under reduced pressure.

Process for preparing 2,2'-dimethyl-1,1'binaphthyl and

2-(4-Isobutylphenyl)-propionic acid is purified by subjecting it to a vacuum rectification, in which the temperature is below the decomposition temperature of the acid.

Process for purifying 2-(4-isobutylphenyl)-propionic acid by vacuum

A process for separating m- and p-dichlorobenzene by extractive rectification with an extractant and removal of this extractant. Using as extractant an alkylene carbonate of the formula ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical to or different from one another and each is hydrogen, methyl or ethyl, with the proviso that together the radicals R.sup.1 to R.sup.4 do not contain more than 6 carbon atoms. The process of the invention makes it possible to separate off the m-isomer in high purity.

Separation of m- and p-dichlorobenzene

The pair of substances for absorption heat transformers consists of methanol and tetraethylene glycol dimethyl ether.

Pair of substances for absorption heat transformers

Brine (an aqueous solution of alkali metal chlorine) which is electrolyzed according to the amalgamation process, generally contains small amounts of mercury. It has been found that these traces of mercury are entrained with the evaporated water in a considerable amount when applying evaporation cooling to the brine. In order to keep these losses as low as possible, a pH of from 7 to 9.0 and a redox potential more than 1391-6.66(pH)-5.94(pH).sup.2 but not more than 1100 mV (based on the potential of the hydrogen electrode) is adjusted by adding chlorine or alkali metal hypochlorite and optionally alkali metal hydroxide to the brine.

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Hofheim, Germany

Adolf Schmidt