|
Results for FIELD_OF_SEARCH: 544/339
Showing 1 - 10 of 612
An .alpha.-indanthrone pigment having improved tinctorial and technological properties is produced by swelling .gamma.-indanthrone in sulfuric acid of from 73 to 80 percent strength by weight at from 20.degree. to 50.degree. C. in the presence of from 0.1 to 20% by weight, based on indanthrone, of a hydroxylammonium salt, a hydrazinium salt, amidosulfonic acid, urea, a salt of urea, formaldehyde or paraformaldehyde or a mixture of these. After precipitation in water which may or may not contain ...
A process for the manufacture of dianthraquinonyl-N,N'-dihydroazine, which comprises reacting 1-nitroanthraquinone in mixtures of water, alcohols and alkali metal hydroxides at elevated temperature with hydrazine or hydroxylamine compounds, subsequently removing the alcoholic constituents from the reaction mixture, adding dimethyl sulfoxide, and, if desired, further amounts of alkali metal hydroxides, and bringing the reaction to completion at elevated temperature.
7,16-Dichlorodianthraquinone-N,N'-dihydroazine (I) ##STR1## is prepared by condensing 1-amino-3-chloroanthraquinone (II) in the presence of an alkaline condensing aid, of an oxidizing agent and of a urea derivative (III) ##STR2## (R: identical or different alkyl groups having 1 to 4 carbon atoms, which may be joined together to form a 5- or 6-membered ring that contains the urea group).
A process for preparing dianthraquinone-N,N'-dihydroazine (I) ##STR1## and its chlorination products (Ia) ##STR2## where n is 1 or 2, by condensation of 1-aminoanthraquinone (II) in the presence of an alkaline condensing aid, an oxidizing agent and a cyclic urea derivative at from 80.degree. to 150.degree. C. and subsequent purification and/or chlorination comprises using N,N'-dimethylpropyleneurea as the urea derivative.
Ecteinascidins (Et's), isolated from the Caribbean tunicate Ecteinascidia turbinata, protect mice in vivo against P388 lymphoma, B16 melanoma, M5076 ovarian sarcoma, Lewis lung carcinoma, and the LX-1 human lung and MX-1 human mammary carcinoma zenografts.
Crude indanthrone is milled, with or without other additives, to reduce and normalize particle size and distribution to a sub-pigmentary, near amorphous, state. The resulting highly aggregated crude powder is then treated with a heterogeneous solvent system of water and an alkyl ester of an aromatic carboxylic acid, such as methyl benzoate, to de-aggregate and grow the particles back to a pigmentary size. The conditions of the solvent treatment can be controlled with respect to temperature, time...
Hexaazatriphenylene hexanitrile and various derivatives therefrom including its hexacarboxamide, hexacarboxylic acid and hexaacid salts and metal complexes, lower alkyl hexaesters of the hexacarboxylic acid, and hexacarboxylic trisanhydride are described along with their preparations initiating with reacting hexaketocyclohexane octahydrate with excess diaminomaleonitrile in acetic acid, preferably at reflux temperature, to provide the hexanitrile from which the other derivatives are prepared.
A process for producing dianthraquinone-N,N'-dihydrazine or its chlorination product, which comprises condensing 1-aminoanthraquinone at an elevated temperature in the presence of 1,3-dimethyl-2-imidazolidinone using an oxidizing agent and an alkaline condensing agent, and subjecting the resulting condensation product to a treatment known per se.
Diketopiperazine compounds designated N-methylepiamauromine, epiamauromine and cycloechinulin have been isolated from the sclerotia of the fungi Aspergillus ochraceus. The compounds are effective for controlling Coleopteran and Lepidopteran insects. The compounds have the structures: ##STR1## wherein: R is a hydrogen atom or a methyl group, such that the compound formed when R is a hydrogen atom is designated epiamauromine and the compound formed when R is a methyl group is designated N-methylep...
Silico-dihydrogen sulfate is produced by reacting and slowly adding a dry alkali metal silicate or an alkaline earth metal silicate to concentrated sulfuric acid in the ratio of 1:4 mols, and then subsequently adding 2 mols of concentrated sulfuric acid to complete the reaction.
|
|