Chromogenic 4,4-diaryldihydroquinazolones

A chromogenic quinazolone of the formula ##STR91## wherein one of the radicals X.sup.4, X.sup.5 or X.sup.6 stands for NY.sup.4 Y.sup.5 and the others, independently of each other, denote hydrogen, halogen, C.sub.1 -C.sub.18 -alkyl, optionally chlorine- and/or C.sub.1 to C.sub.12 -alkyl-substituted phenyl, C.sub.1 - to C.sub.12 -alkanoylamino, optionally chlorine- and/or C.sub.1 - to C.sub.12 -alkyl-substituted benzoylamino, optionally C.sub.1 - to C.sub.4 -alkyl-, C.sub.1 - to C.sub.4 -alkoxy-, chlorine- or phenyl-substituted indolyl or piperidyl radicals, NY.sup.4 Y.sup.5, OY.sup.6 or SY.sup.6,

• R.sup.3 denotes hydrogen, C.sub.1 - to C.sub.18 -alkyl, cyclohexyl or optionally chlorine- and/or C.sub.1 - to C.sub.18 -alkyl-substituted benzyl or phenyl radicals,
• R.sup.4 denotes a radical of the formulae ##STR92## U.sup.1 to U.sup.7 denote hydrogen, optionally fluorine-, chlorine-, cyano-, C.sub.1 - to C.sub.4 -alkoxycarbonyl- and/or C.sub.1 - to C.sub.4 -alkoxy-carrying C.sub.1 - to C.sub.30 -alkyl, optionally chlorine- and/or C.sub.1 - to C.sub.18 -alkyl-carrying cyclohexyl, optionally chlorine-, bromine-, nitro-, C.sub.1 - to C.sub.18 -alkyl, C.sub.1 - to C.sub.18 -alkoxy, C.sub.1 - to C.sub.18 -alkylthio, C.sub.1 - to C.sub.18 -monoalkylamino- or -dialkylamino-, C.sub.1 - to C.sub.18 -alkylsulphonyl-, cyano- and/or C.sub.1 - to C.sub.18 -alkoxycarbonyl-carrying phenyl, benzyl, naphthyl, picolyl, pyridyl, quinolyl, pyrimidyl, pyrazinyl, triazinyl, triazolyl, thiadiazolyl, tetrazolyl, indolyl, optionally benzo-fused imidazole, oxazole or thiazole radicals,
• Y.sup.4, Y.sup.5 and Y.sup.6, independently of one another, denote hydrogen, optionally chlorine-, cyano-, C.sub.1 - to C.sub.4 -alkoxycarbonyl- or C.sub.1 - to C.sub.4 -alkoxy-substituted C.sub.1 - to C.sub.18 -alkyl, cyclohexyl or phenyl or benzyl, each of which can be substituted by chlorine, C.sub.1 - to C.sub.12 -alkyl or C.sub.1 - to C.sub.12 -alkoxy, C.sub.1 - to C.sub.4 -alkyl-substituted piperidyl
• the rings A, B and C can be substituted by chlorine, C.sub.1 - to C.sub.4 -alkyl, C.sub.1 - to C.sub.4 -alkoxy, optionally chlorine-, C.sub.1 - to C.sub.4 -alkyl or C.sub.1 - to C.sub.4 -alkoxy-substituted phenoxy or phenylamino and/or C.sub.1 - to C.sub.4 -alkanoylamino, or
• NY.sup.4 Y.sup.5 denotes an optionally chlorine-, C.sub.1 - to C.sub.4 -alkyl- or aryl-, in particular phenyl-, substituted pyrrolo, pyrrolidino, piperidino, pipecolino, morpholino, pyrazolo or pyrazolino radical.