Abstract: A process for preparing perylene-3,4:9,10-tetracarboxylic dianhydride, comprising: dimerizing a naphthalene-1,8-dicarboximide of the formula IIa; reoxidizing the resulting alkali metal salt of the leuco form of the perylene-3,4:9,10-tetracarboxylic diimide of the formula Ia; hydrolyzing the diimide to the tetraalkali metal salt of perylene-3,4:9,10-tetracarboxylic acid in the presence of an inert organic solvent, of an alkali metal base and of water; and subjecting the tetraalkali metal salt of perylene-3,4:9,10-tetracarboxylic acid to the action of an aqueous inorganic acid to convert it into perylene-3,4:9,10-tetracarboxylic dianhydride; wherein R3 is cyclohexyl or phenyl which may each be substituted by up to three C1-C4-alkyl radicals, and the dimerizing is in a substantially homogeneous reaction medium consisting essentially of an apolar aprotic organic solvent and an alkali metal base.

Abstract: A process for preparing perylene-3,4:9,10-tetracarboxylic dianhydride, comprising: dimerizing a naphthalene-1,8-dicarboximide of the formula IIa; reoxidizing the resulting alkali metal salt of the leuco form of the perylene-3,4:9,10-tetracarboxylic diimide of the formula Ia; hydrolyzing the diimide to the tetraalkali metal salt of perylene-3,4:9,10-tetracarboxylic acid in the presence of an inert organic solvent, of an alkali metal base and of water; and subjecting the tetraalkali metal salt of perylene-3,4:9,10-tetracarboxylic acid to the action of an aqueous inorganic acid to convert it into perylene-3,4:9,10-tetracarboxylic dianhydride; wherein R3 is cyclohexyl or phenyl which may each be substituted by up to three C1-C4-alkyl radicals, and the dimerizing is in a substantially homogeneous reaction medium consisting essentially of an apolar aprotic organic solvent and an alkali metal base.

Abstract: A process for preparing perylene-3,4:9,10-tetracarboxylic diimides of the general formula I comprising dimerizing a naphthalene-1,8-dicarboximide of the formula II in a reaction medium consisting essentially of an apolar aprotic organic solvent and an alkali metal base and subsequently reoxidizing the resulting alkali metal salt of the leuco form of the perylene-3,4:9,10-tetracarboxylic diimide in the presence of a polar solvent.

Abstract: A process for preparing perylene-3,4:9,10-tetracarboxylic diimides of the general formula I where R is C1-C30-alkyl whose carbon chain may be interrupted by one or more —O— moieties and/or which may be substituted by one or more substituents selected from the group consisting of C5-C8-cycloalkyl (which may be substituted by one or more C1-C6-alkyl substituents), phenyl or phenyl-C1-C6-alkyl (which may each be substituted by one or more C1-C18-alkyl and/or C1-C6-alkoxy substituents), —OCOR1, —N(R1)2, —SO2NH2, —SO2N(R1)2, —CON(R1)2 and —COOR1; C5-C8-cycloalkyl whose carbon skeleton may be interrupted by one or more moieties selected from the group consisting of —O—, —S— and —NR2- and/or which may be substituted by one or more C1-C6-alkyl substituents; phenyl, phenyl-C1-C6-alkyl, naphthyl or hetaryl, which may each be substituted by one or more substituents selected from the group consisting of C1-C18-alkyl, C1-C6-alkoxy, phenylazo, naphthylazo, pyridylazo, pyrimidylazo, cyano, —N(R1)2, —CON(R1)2 and —COO

Abstract: Nickelized shaped articles are produced by electrodeposition of nickel from aqueous acidic baths containing as essential constituents one or more nickel salts, one or more inorganic acids and at least two brighteners by using as brighteners a mixture ofA) from 2 to 98% by weight of one or more cyclic N-allylammonium or N-vinylammonium compounds I ##STR1## where the nitrogen atom is part of a pyridine, quinoline or isoquinoline ring system which may additionally carry one or two C.sub.1 - to C.sub.4 -alkyl substituents or halogen atoms,R.sup.1, R.sup.3 and R.sup.4 are each hydrogen or C.sub.1 - to C.sub.4 -alkyl,R.sup.2 is hydrogen or methyl,m is from 0 to 4,n is from 1 to 4, andX.sup..crclbar. is an n-valent inorganic or organic anion which promotes solubility in water, andB) from 98 to 2% by weight of one or more acetylenically unsaturated compounds IIR.sup.4 --C.tbd.C--R.sup.5 (II)where R.sup.4 and R.sup.5 are identical or different and each is C.sub.1 - to C.sub.

Abstract: The production of shining shaped articles coated with zinc or a zinc alloy by electrodeposition of zinc or a zinc alloy from acidic aqueous electrolytic baths which contain as essential components one or more zinc salts and, where appropriate, salts of the other alloy metals, one or more conducting salts, one or more surfactants and one or more brighteners, entails employing as brighteners compounds of the formula I ##STR1## where R.sup.1 is C.sub.1 -C.sub.8 -alkoxy, phenoxy, benzyloxy, amino, C.sub.1 -C.sub.6 -alkylamino or di(C.sub.1 -C.sub.6)alkylamino,R.sup.2 is C.sub.1 -C.sub.4 -alkyl, phenyl, benzyl or the meanings of R.sup.1, andAr is phenyl or naphthyl which can additionally be substituted by one to three C.sub.1 -C.sub.4 -alkyl groups or C.sub.1 -C.sub.4 -alkoxy groups.

Abstract: Heterocyclic compounds which are useful as bleach activators or optical brighteners in washing and cleaning agents have the formula ##STR1## where the variables have the following meanings: X is O, S or the group N--R.sup.3, where R.sup.3 is hydrogen, C.sub.1 -C.sub.25 -alkyll C.sub.1 -C.sub.25 -acyl or an aryl group of up to12 carbon atoms,Y is CH or N,R.sup.1 for X=S or N--R.sup.3 is hydrogen, a C.sub.1 -C.sub.25 -alkyl or C.sub.2 -C.sub.25 -alkenyl group or a phenyl radical which may be additionally substituted by one or two C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, hydroxyl, carboxyl, sulfo, amino, C.sub.1 -C.sub.4 -acylamino, nitro or cyano groups or chlorine or bromine atoms, which substituents, if there are two of them, may be identical or different,R.sup.1 for X=O is phenyl, o-, m- or p-tolyl, p-chlorophenyl, m-nitrophenyl, m-methoxyphenyl or m-methylsulfonylphenyl,R.sup.2 for X=S or N--R.sup.3 is hydrogen, a C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.