摘要 |
The lactone compounds have the formula …<IMAGE>… in which… Ar denotes 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 denotes hydrogen, halogen, lower alkyl or lower alkoxy,… R2 denotes 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, each denote hydrogen, unsubstituted or halogen-, hydroxyl-, cyano-, tetrahydrofuryl- or lower alkoxy-substituted alkyl, acyl, cycloalkyl or unsubstituted or halogen-, cyano-, nitro-, trifluoromethyl-, lower alkyl-, lower alkoxy- or lower alkoxycarbonyl-substituted aralkyl or aryl or the substituent pairs (X1 and X2) and (X3 and X4) each together with the joint nitrogen atom denote a five- or six-membered, preferably saturated, heterocyclic radical, and… the ring A is unsubstituted or substituted by halogen, nitro, lower alkyl, lower alkoxy, lower alkylthio, lower alkoxycarbonyl, amino, mono(lower alkylamino) or di(lower alkylamino). …<??>These novel lactone compounds are suitable in particular as colour formers in pressure-sensitive or heat-sensitive recording materials and produce intensive yellow, orange or red colourations. |