Cassella Aktiengesellschaft

Hoechst Aktiengesellschaft

Friedrich Schophoff

Ulrich Buhler

Rudolf Binder

Theodor Papenfuhs

Reinhard Kuhn

Klaus Hofmann

Margareta Boos

Kuno Reh

Wolf Weidemuller

The present invention relates to a process for the preparation of finished dyeings of high fastness to thermomigration on fibre materials consisting completely or partly of polyester, characterized in that the material is dyed with one or more dyestuffs of the general formula I ##STR1## wherein R denotes linear (C.sub.1 -C.sub.3)-alkyl or (C.sub.3 -C.sub.6)-alkyl which is interrupted by an oxygen atom and

Process for the preparation of finished dyeings which are fast to

The present invention relates to the .beta.-modification of the dye of the formula I ##STR1## to a process for its preparation, to its use, and to a dye preparation containing it.

Color-stable beta-modification of a monoazo dye, a process for its

Azo disperse dyestuffs are prepared by diazotization and coupling in an aqueous phase, the coupling being carried out in the presence of an ester of a lower aliphatic carboxylic acid.

Preparation of azo dyestuffs by diazotization and coupling in the

2,4-Dinitrophenyl ethers are prepared by reacting a 2,4-dinitrochlorobenzene or 2,4-dinitrobromobenzene with an alkali metal alcoholate in a non-polar, inert solvent, at a temperature from -25.degree. C. to 50.degree. C.

Process for the preparation of 2,4-dinitrophenyl ethers

Process for the preparation of compounds of the formula (I) ##STR1## in which R denotes a C.sub.1 -C.sub.4 -alkyl radical which is optionally substituted by C.sub.1 -C.sub.4 -alkoxy groups, or a phenyl radical which can be substituted by alkyl or alkoxy groups having 1 to 4 carbon atoms or by chlorine or bromine atoms, or, together with R.sub.2, denotes an alkylene bridge --(CH.sub.2).sub.n -- in which n is the number 3 or 4, R.sub.1 denotes a hydrogen atom or an alkyl radical having 1 to 4 carbon atoms, and R.sub.2 represents a hydrogen atom or an alkyl radical having 1 to 4 carbon atoms, or, together with R, represents an alkylene bridge --(CH.sub.2).sub.n -- in which n has the meaning mentioned, by reacting 2,4-dinitrochlorobenzene with an alcohol of the formula (II) ##STR2## in which R, R.sub.1 and R.sub.2 have the meanings mentioned above, in the presence of lithium oxide or lithium hydroxide at temperatures from 0.degree. to 5.degree. C., if appropriate neutralizing the reaction mixture with a non-volatile, weak acid which is soluble in the reaction medium, and subsequently removing by distillation the alcohol of the formula (II), present in excess, then adding sufficient water at 20.degree. to 80.degree. C. for the lithium chloride formed to dissolve completely, and separating off, from the aqueous salt phase, the 2,4-dinitrophenol alkoxyalkyl ether which has separated out in a solid or liquid phase.

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Frankfurt am Main, Germany

Friedrich Schophoff