Bayer Aktiengesellschaft

Adolf Winkler

Josef Bremen

Bruno Kruger

Alexander Klausener

Horst Behre

Helmut Hurnik

Erich Hammerschmidt

G&uuml;nter Rauchschwalbe

Gunter Hentze

Ralf-Ingo Schenkel

Andreas Groschl

Gerhard Trummelmeyer

The invention relates to a process for the alkylation of 3,4-dihydroxythiophene-2,5-dicarboxylic esters or their alkali metal or alkaline earth metal salts with alkylating agents in a polar diluent in the presence of quaternary onium salts.

Process for the alkylation of 3,4-dihydroxythiophene-2,5-dicarboxylic esters

A process as been found for the removal of water from reaction mixtures of acids or acid anhydrides or of aqueous alkali metal hydroxide solutions with alcohols using vapor permeation/pervaporation at the boiling point of the reaction mixture, which includes initially introducing the lowest-boiling educt in less than the stoichiometric amount, based on the other particular educt, together with this other educt, heating the reaction mixture to the boiling point and freeing the vapor mixture, which is formed from the boiling reaction mixture and includes chiefly water and the lowest-boiling component, from water on a membrane, recycling the vapor mixture which has been freed from water into the reaction mixture and topping up the reaction mixture with the lowest-boiling educt in the course of the reaction.

Removal of water from reaction mixtures

The new polyester polyols, which have an acid value below 10, a hydroxyl value of 50 to 200, a hydroxyl functionality above 2 and a number average molecular weight M.sub.n of 800 to 5,000 and which are liquid at 23.degree. C. or are homogeneously soluble in di-2-ethylhexyl phthalate in a concentration of at least 70% by weight, the viscosity of the 70% solution being from 1 to 35 Pa.s, are used as anchoring agents for polymer systems and as polymeric plasticizers.

Polyester polyols and their use as anchoring agents for polymer systems

The invention relates to a process for the preparation of 1-benzoylamino-8-hydroxynaphthalene-4,6-disulphonic acid (benzoyl-K acid) by reacting 1-amino-8-hydroxynaphthalene-4,6-disulphonic acid (K acid) with benzoylating agents, according to which process mixtures of aminonaphtholdisulphonic acid isomers are used instead of pure K acid, which mixtures contain over 40% by weight of K acid, relative to the total amount of diazotizable compounds in the mixture of isomers, and in which no other single isomer has a proportion which exceeds 10% by weight of the total amount of diazotizable compounds in the mixture of isomers.

Process for the preparation of

The invention relates to a process for the preparation of nitroanilines by the reaction of chloronitrobenzenes with ammonia at elevated temperature and under elevated pressure, and in the presence of chlorinated aromatic hydrocarbons. Nitroanilines are important precursors and intermediate products for the preparation of dyestuffs, pharmaceuticals and plant protection agents.

Process for the preparation of nitroanilines

A process for the production of an arylsulphonium salt, comprising reacting an aromatic compound of the formula

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Leverkusen, Germany

Adolf Winkler