Hoechst Aktiengesellschaft

Otto Fuchs

Adolf Kroh

Ernst Spietschka

Helmut Troster

Erwin Dietz

Klaus Hunger

Konrad Baessler

Wolfgang Teige

Siegfried Planker

Michael Maikowski

Robert Gutbrod

Reinhard Zunker

Dieter Weber

Aloys Kirsch

2,5-Bis-(4'-aminophenyl)-1,3,4-oxadiazoles which are chlorinated in the phenyl nuclei are obtained by condensing hydrazine or a hydrazine yielding agent with equal or different chlorinated benzoic acids or acylating acid derivatives having in para-position to the acid group an amino group or a group capable of being transformed into the amino group, and, thereafter, effecting ring closure of the so-obtained bis-hydrazide to yield the oxadiazole. The products are bis-diazo components, especially for pigments having a very high tinctorial strength, clear and pure shades, a good fastness to light, to heat and to solvents.

1,3,4-Oxadiazoles

The invention relates to a process for coloring water-insoluble thermoplastic plastics with dyestuffs of the formula ##STR1## The dyestuffs are added to the melt of the thermoplastic plastic or to its precursors.

Process for mass coloring thermoplastic plastics

Compositions of linear trans-quinacridones containing at least one component (I) selected from unsubstituted, chloro- and methyl-substituted quinacridone and at least one component (II) selected from bis-(carbamoyl)-quinacridones, the carbamoyl groups of which are unsubstituted, N-mono-alkyl substituted or N,N-dialkyl-substituted, are pigments useful for coloring plastics and especially lacquers. These compositions are preferably prepared by joint ring closure of the corresponding 2,5-dianilino-terephthalic acids or esters.

Quinacridone mixtures, process for their manufacture and their use as

Monoazo compounds of the formula ##STR1## wherein A stands for --NH--CO--NH--, --NH--CO--CO--NH-- or --NH--CO--NH--CO--,

Monoazo compounds, process for their manufacture and their use

Monoazo compounds of the general formula ##STR1## in which R is hydrogen, methyl or ethyl. The monoazo compounds are valuable pigments which are especially useful for coloring baking varnishes and plastics. They also exhibit characteristics of good fastness to light, weathering, migration, especially overvarnishing and heat stability.

Monoazo compounds deriving from 5-amino-benzimidazole-2-one-6-carboxylic

Easily dispersible preparations of organic pigments are obtained by coating the pigment particles with essentially colorless aromatic compounds having a molecular structure being similar to that of the pigment and having an aliphatic chain of more than 5 carbon atoms. These preparations are stable to flocculation and useful for pigmenting hydrophilic and hydrophobic media.

Pigment preparations

The catalytic hydrogenation of o-nitro-chlorobenzene in aqueous alkali metal hydroxide solution with addition of an aromatic non-watermiscible solvent at an elevated temperature and under pressure using a noble metal catalyst and a polycyclic quinone as a co-catalyst leads to high and well-reproducible yields of 2,2'-dichloro-hydrazobenzene when the quinone is a derivative of anthraquinone, especially a hydroxy-anthraquinone. The product is obtained in so high a quality that it can be transformed without isolation or purification into 3,3'-dichlorobenzidine.

Process for the preparation of 2,2'-dichloro-hydrazobenzene

Unsubstituted linear trans-quinacridone of the gamma-crystal modification is obtained by cyclization of 2,5-dianilino-terephthalic acid with the 2.5 to 4-fold quantity of polyphosphoric acid or of an acidic polyphosphoric acid methyl ester, followed by hydrolysis of the condensation product in water, intensive grinding of the aqueous crude quinacridone in the presence of an alcohol or ketone and heating of the resulting product to 80.degree. to 200.degree. C.

Process for the manufacture of the gamma-crystal modification of linear

2,5-Diarylamino terephthalates are obtained in good yields and excellent purity when the aromatic nitro compound used for oxidizing the corresponding dihydro-2,5-diarylamino terephthalate contains the aromatic radical of said diarylamino groups, i.e. when the amine formed during the oxidation is that from which said diarylamino groups device. The products yield very pure quinacridone pigments and allow the synthesis of only one isomer of substituted quinacridones.

Process for preparing pure substituted 2,5-diarylamino-terephthalates

Naphthalimide-4,5-dicarboxylic acids of the formula ##STR1## or the anhydrides thereof, wherein R is alkyl having 1 to 8 carbon atoms or hydroxyalkyl or alkoxyalkyl having each 1 to 6 carbon atoms in the alkyl or alkoxy portion, which are obtained by reacting an alkali metal salt of naphthalene-1,4,5,8-tetracarboxylic acid in an aqueous solution with amines of the formula

Naphthalimide-4,5-dicarboxylic acids

Treating compounds of the formula ##STR1## in which the nuclei marked 'A' and 'B' can be substituted by halogen, lower alkyl, lower alkoxy or phenyl, with acid binding agents at elevated temperatures in polar organic solvents yields compounds of the formula ##STR2## in which A and B have the same meaning. The products are dyestuffs of high brillancy, pure shades, high fluorescence, excellent tinctorial strength and good fastness to light.

Benzothioxanthenes

Novel naphthalimide-4,5-dicarboxylic acids of the general formula ##STR1## or the anhydrides thereof, wherein R.sub.1 is hydrogen, hydroxy, amino, alkyl having 1 to 8 carbon atoms, hydroxyalkyl, alkoxyalkyl, aminoalkyl, monoalkylaminoalkyl, hydroxyalkoxyalkyl, alkoxyalkoxyalkyl, carbalkoxyalkyl, carboxyalkyl or phenylalkyl having each 1 to 6, preferably 1 to 4 carbon atoms in the alkyl or alkoxy portion or phenyl substituted by 1 to 3 halogen atoms, amino, alkyl, alkoxy, acylamino, acyl having each 1 to 4 carbon atoms, benzoyl or Carboxyl, and a process for preparing them, wherein naphthalene-1,4,5,8-tetracarboxylic acid, the mono- or dianhydride thereof are reacted as alkali salts in an aqueous solution with amines of the formula

Benzoxanthene- and benzothioxanthene-dicarboxylic acid imide dyestuffs of the general formula ##SPC1## Wherein

Benzoxanthene and benzothioxanthene dicarboxylic acid imide dyestuffs

Process for preparing naphthoylene-arylimidazo-peri-dicarboxylic acid-imide-compounds of the formula ##SPC1## Wherein R.sub.1 is hydrogen, hydroxy or amino, phenyl, alkyl having 1 to 8 carbon atoms, hydroxyalkyl, alkoxyalkyl, amino-alkyl, mono- or dialkylaminoalkyl, hydroxyalkoxyalkyl, alkoxyalkoxyalkyl, carbalkoxyalkyl, carboxylalkyl or phenyl-alkyl having each 1 to 6, preferably 1 to 4 carbon atoms in the alkyl or alkoxy portion and R is hydrogen or halogen, alkyl, alkoxy, carbalkoxy having each 1 to 4 carbon atoms, nitro, cyano, carbonamido, mono- or dialkylcarbonamido or sulfonamido, mono- or dialkylsulfonamido and n represents the integers 1 to 3, in which process naphthalimide-4,5-dicarboxylic acids of the general formula ##SPC2## Or the anhydride thereof are condensed in an aqueous medium with a diamine of the general formula ##SPC3## At temperatures of from 80.degree. to 160.degree.C. R.sub.1, R and n having the above meanings.

Growing community of inventors

Frankfurt am Main, Germany

Otto Fuchs