Abstract: The present invention relates to new chromogenic amino acid esters and peptide esters of hydroxyisoquinolines and hydroxyquinolines, processes for their preparation and the use of the new esters as substrates for the analytical detection of esterolytic and/or proteolytic enzymes, for example in body fluids, the esters being incorporated into test agents, in particular test strips, in a suitable manner. The new esters are particularly used for the detection of leukocytes, in particular in urine.

Abstract: Hetarylmethane leuco dyestuffs of the formula ##STR1## wherein R denotes halogen, alkyl, alkoxy, aryl or aryloxy,A denotes an aromatic-carbocyclic or -hetero-cyclic radical,B denotes hydrogen, halogen, alkyl, aryl, alkylcarbonyl, arylcarbonyl, amino, monoalkylamino, dialkylamino, arylamino, aralkylamino or acylamino,X denotes CH or N,Y denotes ##STR2## R.sub.6 denotes hydrogen or alkyl, m denotes 4-6 andn denotes O and 1-4 andwherein the cyclic and acyclic radicals in turn can be substituted by nonionic radicals, are used as color formers in pressure-copyable and thermoreactive recording materials.

Abstract: Metal complexes, particularly copper and nickel complexes of azo dyes corresponding to general formula (I) are suitable as color dyes for the production of color images by the dye diffusion transfer process. The dyes are (in non-metallized form), in the form of so-called "dye-releasers", bound to a redox-active carrier radical provided with a ballast group, which dye-releasers are associated to a light-sensitive silver halide emulsion layer. During development, the metallizable dyes are image-wise released and are converted, after diffusion into a light-receiving layer, into the corresponding metal complexes ##STR1## wherein E represents an electron acceptor radical; andK represents the radical of an azo coupler component, derived from an open-chain or closed ring ketomethylene compound, a cyclic enamine compound or a phenolic compound.

Abstract: Process for the preparation of dimethyl succinylosuccinate, or the disodium salt thereof, by condensation of dimethyl succinate in a 35-45 percent by weight solution of sodium methylate in methanol, and a process for the preparation of dianilinodihydroterephthalic acids, the dimethyl esters and salts thereof, and of dianilinoterephthalic acids, and the dimethyl esters and salts thereof, starting from the disodium salt of dimethyl succinylosuccinate prepared according to the new process, without intermediate isolation.

Abstract: Azo dyes of formula II are released on development from dye releasers which are associated with a light-sensitive silver halide emulsion layer. The azo dyes are chelatable and form with metal ions blue or cyan dye-metal-complex image dyes. ##STR1## In the formula A.sup.1 and A.sup.2 represent electronegative substituents whose meta-sigma values .sigma..sub.m (according to D. H. McDaniel and H. C. Brown in J. Org. Chem. 23, 420 et seq (1958) conform to at least one of the following three relationships:1. .sigma..sub.m (A.sup.1), .sigma..sub.m (A.sup.2) +0.332. .sigma..sub.m (A.sup.1) +.sigma..sub.m (A.sup.2) +0.75;3. .sigma..sub.m (A.sup.1) +0.33 and A.sup.2 represents--SO.sub.2.sup.XX represents H, --OH, --NH.sub.

Abstract: Cyan images may be prepared by the dye diffusion transfer process, using dye-releasers which on development release diffusible dyes capable of forming light-fast cyan metal-dye-complexes particularly with copper or nickel ions. As also the dye-releasers are capable of complexation, cyan images can be prepared not only from the released dyes but also from the dye-releasers ("retained image"). Released dyes and dye-releasers of the present invention contain a chromophor of the following formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4, which may be the same or different, each represents --H, --F, --Cl, --Br, --CN, --NO.sub.2, --CF.sub.3, --OCF.sub.3, --SCF.sub.3, alkyl, alkoxy, alkylthio, acylamino, alkylsulfonyl, arylsulfonyl, --CO--X or --SO.sub.2 --Y or two adjacent groups R.sup.1 -R.sup.4 together constitute a condensed benzene ring which may contain further substituents;R.sup.5 represents hydrogen or a substituent having an electron donor character;R.sup.