Cassella Aktiengesellschaft

Ulrich Kussmaul

Johannes Becherer

Rolf Muller

Manfred Langer

Ulrich Riegel

Friedrich Engelhardt

Reinhard Handte

Klaus Kuhlein

Manfred Mayer

Uwe Stuven

Herbert Wille

Kuno Reh

Dieter Ferchland

Hans J Nestler

Reinhardt Handte

The present invention relates to hydrophilic, swellable graft polymers which comprise, in a random distribution, from 0.5 to 50% by weight of radicals of the general formula I ##STR1## and radicals of the general formula II ##STR2## from 49 to 99% by weight of radicals of the general formula III ##STR3## containing an acid group, and from 0.1 to 2% by weight of radicals of a crosslinking agent which are derived from monomers containing at least two olefinically unsaturated double bonds, where the radicals R.sup.1 to R.sup.4, X and Y and n and m are where X and Y, independently of one another are COCH.sub.3, CH.sub.2 COOR.sup.2, COCH.sub.2 CH.sub.2 COOH ##STR4## n and m, independently of one another, are 2 to 300, R.sup.1 is hydrogen or methyl, R.sup.2, independently of one another, are hydrogen, methyl or ethyl, R.sup.3 is the carboxyl group, the sulphonyl group, the phosphonyl group, which is optionally esterified by means of alkanol having 1 to 4 carbon atoms, or a group of the formula ##STR5## to the preparation thereof, and to the use thereof as absorbents for water and aqueous solutions.

Hydrophilic, swellable graft polymers

The process for the preparation of 2-chlorobenzoxazoles of the formula ##STR1## wherein R.sup.1 and R.sup.2, independently of one another, are hydrogen or halogen comprising reacting a benzoxazolinone of the formula ##STR2## with a molar excess of phosphorus pentachloride.

Process for the preparation of 2-chlorobenzoxazoles

2-Mercaptobenzoxazoles of the formula ##STR1## wherein R is hydrogen or halogen and M is hydrogen or a metal atom, are prepared by reacting an ortho-aminophenol or metal salts thereof, with an alkali metal trithiocarbonate in aqueous solution.

Process for the preparation of 2-mercaptobenzoxazoles

A compound of the formula ##STR1## is reacted with a phenol of the formula ##STR2## in the presence of an acid to produce a heterocyclic phenyl ether of the formula ##STR3## wherein each R is independently selected from halogen, trifluoromethyl, nitro, cyano, alkyl having 1 to 4 carbon atoms, alkoxy having 1 to 4 carbon atoms or alkylthio having 1 to 4 carbon atoms;

Process for the preparation of heterocyclic phenyl ethers

In the process for preparing 2-chlorobenzoxazoles of the formula ##STR1## wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is independently of one another, H, chloro or alkyl having 1 to 4 carbon atoms, which comprises reacting chlorine with 2-mercaptobenzoxazoles of the formula ##STR2## wherein the improvement comprises providing a melt of previously prepared 2-chloro-benzoxazole, adding the 2-mercaptobenzoxazole reactant to the 2-chlorobenzoxazole melt and simultaneously or subsequently passing chlorine into the melt, with the proviso that substituents R.sup.1 to R.sup.4 are identical in both the 2-chlorobenzoxazole melt and the 2-mercaptobenzoxazole reactant.

Process for preparing 2-chlorobenzoxazoles

An improved process for preparation of arylisocyanide dichloride by chlorinating N-arylformamide in the presence of thionyl chloride wherein the improvement comprises preparing the N-arylformamide by formylation of an arylamine having 6 to 12 aryl carbon atoms with a formylating agent in an inert solvent.

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Karben, Germany

Ulrich Kussmaul