Abstract: Compounds of formula (1) ##STR1## wherein A and B are identical or different alkyl, aralkyl or cycloalkyl groups or carbocyclic or heterocyclic aromatic radicals, R.sub.1 and R.sub.2 are hydrogen atoms or substituents which do not impart solubility in water, are particularly suitable as photoconductive substances.

Abstract: A process for the preparation of 1,4-diketopyrrolo-[3,4-c]pyrroles of the formula ##STR1## wherein each of R.sub.1 and R.sub.2 independently of the other is an isocyclic aromatic or non-basic heterocyclic aromatic radical, which process comprises reacting 1 mole of the compound of formula ##STR2## wherein M is a metal atom, Z is alkyl or aryl, X is halogen or acetate, and m is a value from 0 to 2, with 1 mole of a compound of the formulaYCH.sub.2 COOZ (III)wherein Y is halogen, and with 1 mole of a nitrile of the formulaR.sub.1 --CN (IV) or R.sub.2 --CN (V)in an organic solvent and at elevated temperature, and isolating the compound of formula I.The compounds obtained according to the invention are suitable for pigmenting organic material of high molecular weight.

Abstract: Compounds of the formula ##STR1## in which R.sub.1 and R.sub.2 are unsubstituted or substituted phenyl or naphthyl, and R.sub.3 and R.sub.4 are alkyl, alkoxycarbonyl, phenyl, benzoyl or benzyl, are suitable for dyeing high molecular weight organic material.

Abstract: A process for the preparation of 1,4-diketopyrrolo-[3,4-c]pyrroles of the formula ##STR1## wherein each of R.sub.1 and R.sub.2 independently of the other is an isocyclic or heterocyclic aromatic radical, which process comprises reacting 1 mole of a disuccinate with 2 moles of a nitrile of the formulaR.sub.1 --CN (II)orR.sub.2 --CN (III)or with 1 mole of a nitrile of the formula (II) and 1 mole of the nitrile of the formula (III), in an organic solvent and in the presence of a strong base at elevated temperature, and obtaining the compound of formula I from the reaction product by hydrolysis.The pyrrolo-[3,4-c]pyrroles are suitable for pigmenting organic material of high molecular weight.

Abstract: A process for producing a compound of the formula ##STR1## wherein A is aryl or alkyl, R.sub.1 is an aromatic radical and R.sub.2 is hydrogen, alkyl, aryl, cyano, --COOalkyl or --COOaryl, which process comprises reacting 1 mol of an aromatic nitrile of the formula R.sub.1 --CN (II) with 1 mol of an acetic ester of the formula (X)(R.sub.2)CH--COOA (III) in which X is halogen, in the presence of zinc, in an inert organic solvent and at a temperature of less than 80.degree. C.; hydrolyzing in an alkaline medium the formed reaction product; and then isolating the compound of the formula I.The compounds of the formula I are valuable intermediates for producing heterocyclic compounds.

Abstract: A process for producing bismethine isoindolines of the formula ##STR1## in which process the condensation of 1 mol of any one of the compounds of the formulae ##STR2## with 2 mols of a cyanomethylene compound of the formula NC--CH.sub.2 --R.sub.1 or NC--CH.sub.2 --R.sub.2, or with 1 mol of a cyanomethylene compound of the formula NC--CH.sub.2 --R.sub.1 and 1 mol of a cyanomethylene compound of the formula NC--CH.sub.2 --R.sub.2, wherein the symbols have the meanings defined in the specification, is performed in a polar solvent in the presence of a strong base, and the bismethine isoindoline obtained is isolated from the reaction mixture by hydrolysis.The bismethine isoindolines are suitable for pigmenting high-molecular organic material, particularly lacquers.

Abstract: A process for producing bismethine isoindolines of the formula ##STR1## in which process the condensation of 1 mol of any one of the compounds of the formulae ##STR2## with 2 mols of a cyanomethylene compound of the formula NC-CH.sub.2 -R.sub.1 or NC-CH.sub.2 -R.sub.2, or with 1 mol of a cyanomethylene compound of the formula NC-CH.sub.2 -R.sub.1 and 1 mol of a cyanomethylene compound of the formula NC-CH.sub.2 -R.sub.2, wherein the symbols have the meanings defined in the specification, is performed in a polar solvent in the presence of a strong base, and the bismethine isoindoline obtained is isolated from the reaction mixture by hydrolysis.The bismethine isoindolines are suitable for pigmenting high-molecular organic material, particularly lacquers.

Abstract: A process for the manufacture of o-phenylenediacetonitrile by reacting an aqueous solution of an alkali metal or alkaline earth metal cyanide with an o-xylylene halide optionally in the presence of an emulsifier is provided.