| 摘要 |
Chromogenic lactone compounds of benzopyrano-2H-pyrazoles of the formula <IMAGE> (1) in which Ar is an aryl radical which is unsubstituted or substituted by halogen, nitro, cyano, lower alkyl, lower alkoxy, lower alkylthio, lower alkoxycarbonyl, trifluoromethyl, phenoxy, phenylthio or -NX3X4, R1 is hydrogen, lower alkyl or lower alkoxy, R2 is lower alkyl, phenyl, or phenyl which is substituted by halogen, lower alkyl or lower alkoxy, and X1, X2, X3 and X4, independently of one another, are each hydrogen, alkyl which is unsubstituted or substituted by halogen, hydroxyl, cyano, tetrahydrofuryl or lower alkoxy, or are acyl, cycloalkyl, or aralkyl or aryl, each of which is unsubstituted or substituted by halogen, cyano, nitro, trifluoromethyl, lower alkyl, lower alkoxy or lower alkoxycarbonyl, or the substituent pairs (X1 and X2) and (X3 and X4), in each case together with the common nitrogen atom, are a 5- or 6-membered, preferably saturated heterocyclic radical, and in which the ring A is unsubstituted or substituted by halogen, nitro, lower alkyl, lower alkoxy, lower alkylthio, lower alkoxycarbonyl, amino, mono(lower alkyl)amino or di(lower alkyl)amino. These novel lactone compounds are particularly suitable as color formers in pressure-sensitive or heat-sensitive recording materials, and give intense yellow, orange or red colorations.
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