Abstract: Reaction of pyrazolones and methyleneindolines with orthoformic esters is an advantageous one-step process for preparing asymmetrical methine dyes.

Abstract: Reaction of pyrazolones and methyleneindolines with orthoformic esters is an advantageous one-step process for preparing asymmetrical methine dyes.

Abstract: The present invention relates to a process for preparing compounds of formula (I) ##STR1## wherein A completes an unsubstituted or substituted heteroaromatic ring andB completes an unsubstituted or substituted aromatic ring, by reacting a heterocyclic compound of formula (II) ##STR2## wherein A completes an unsubstituted or substituted heteroaromatic ring, with an aromatic dicarboxylic acid of formula (III) ##STR3## or an anhydride thereof, wherein B completes an unsubstituted or substituted aromatic ring, in an organic solvent in the presence of an aliphatic or aromatic alcohol that is different from both the organic solvent and compounds (I), (II), and (III).

Abstract: Compounds of the general formula (I) or tautomeric forms thereof ##STR1## wherein Ar.sub.1 and Ar.sub.2 independently of one another denote radicals to complete optionally substituted carbocyclic aromatic rings, B denotes an optionally substituted alkylene group or a radical of the formula ##STR2## wherein r represents a number from 1 to 4, the ends of which are in each case bonded to an aromatic C atom of the two radicals Ar.sub.1 and Ar.sub.2, andX.sub.1 and X.sub.2 independently of one another represent a radical of the formulae chosen from the group consisting of ##STR3## these being in each case located in the ring such that the ##STR4## or the ##STR5## group is adjacent to the C--C double bond, wherein Y, Z, R.sub.a and R.sub.b have the meaning, given in the description, are outstandingly suitable for bulk dyeing of plastics.

Abstract: The present invention relates to compounds of the formula (I)R.sup.1 --NH--B--NH--R.sup.2 (I),whereinR.sup.1 and R.sup.2 independently of one another denote an unsubstituted or substituted radical of the formula ##STR1## and B represents an unsubstituted or substituted cycloalkylene-containing bridge member, which are suitable for bulk dyeing of plastics.

Abstract: The new dyestuffs of the formula (I) ##STR1## wherein the substituents R and R.sup.1 and the index n have the meaning given in the description, are outstandingly suitable for dyeing and printing cellulose-containing materials, in particular for the preparation of recording liquids for ink jet recording systems.

Abstract: A process for the preparation of N,N'-disubstituted 1,4-diaminoanthraquinones has been found which is characterized in that 1,4-dihydroxyanthraquinones are reacted with aliphatic or aromatic amines in the presence of a hydroxycarboxylic acid as a condensation auxiliary.

Abstract: Process for the preparation of naphthalene-1,8-dicarboximide which is optionally substituted in the naphthalene ring, characterized in that naphthalene-1,8-dicarboxylic anhydride which is optionally substituted in the naphthalene ring is reacted with an ammonium salt in an aqueous medium at a pH near to the neutral point, the reaction mixture is then acidified to a pH of 1 to 4 and the pH is subsequently adjusted to a value near to the neutral point.