Abstract: Water-soluble black trisazo dyestuffs of the general formula I ##STR1## wherein R denotes hydrogen, alkyl having 1 or 2 carbon atoms, alkoxy having 1 or 2 carbon atoms, acylamino having 2 or 3 carbon atoms or carboxamide and n denotes a number from 0 to 2.5 are suitable for the preparation of recording fluids.

Abstract: A process for the preparation of 2-arylthiobenzoic acids which are useful as intermediates in producing thioxanthene compounds comprises reacting by reacting lithium 2-chlorobenzoate of the formula ##STR1## with lithium thiophenoxide of the formula ##STR2## wherein R is alkyl having 1 to 4 carbon atoms, alkoxy having 1 to 4 carbon atoms, trifluoromethyl, hydrogen, fluorine, chlorine or nitro andn is 1, 2, 3 or 4.

Abstract: Hides, skins and pelts are tanned by use of a tanning agent which comprises the reaction product of acetaldehyde, formaldehyde and a formylamino compound.

Abstract: 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.

Abstract: 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.

Abstract: The aqueous dyestuff formulation of an tetrakisazo direct dyestuff which is stable to alkali and contains at least one aromatic hydroxyl group and/or enol group and at least one group conferring solubility in water, or a mixture of such azo direct dyestuffs, is characterized in that it has a pH value equal to or greater than 12 and is prepared by mixing an azo direct dyestuff which is stable to alkali, water and a tertiary alkali metal phosphate and/or alkali metal metasilicate and/or alkali metal hydroxide, and by choosing the proportions such that the dyestuff formulation contains 5 to 50% by weight of dyestuff and has a pH value equal to or greater than 12. The dyestuff formulation is used, after dilution with water, for dyeing and printing natural or synthetic materials containing hydroxyl groups.

Abstract: The present invention relates to new, pharmacologically valuable 2,4,5,6-tetrahydro-1H-pyrazino-[3,2,1-jk]-carbazoles substituted in the 8-position having the formula I ##STR1## wherein R stands for an alkyl or alkoxy group having 1 to 4 carbon atoms or a fluorine, chlorine or bromine atom comprising reacting a 6,9-disubstituted 1,2,3,4-tetrahydrocarbazol-1-one of the formula II ##STR2## and X denotes a bromine, chlorine or iodine atom or the radical of the formula defined --O--SO.sub.2 --R' and R' is an alkyl radical having 1 to 3 carbon atoms, phenyl or tolyl, with ammonia.