Abstract: The invention relates to a new process for the preparation of substituted aminotriazolinones of the general formula (I) ##STR1## in which R has the meanings mentioned in the description.

Abstract: Highly concentrated stable solutions of color-forming agents of the general formula ##STR1## wherein x denotes hydroxyl, alkoxy, alkenyloxy, aralkoxy, cycloalkoxy, aryloxy, acyloxy, alkylamino, dialkylamino, acrylamino, aralkylamino or arylamino andR denotes alkyl, alkenyl or aralkyl,further isocyclic or heterocyclic rings can be fused onto the rings A, B, C and D and the cyclic and acyclic radicals and the rings A, B, C and D can carry further non-ionic substituents which are customary in dyestuff chemistry, or mixtures thereof, in water-insoluble organic solvents from the group comprising optionally chlorinated hydrocarbons, vegetable oils and phthalic acid esters are used for the preparation of pressure-sensitive recording materials.