| 摘要 |
Azulene squaric acid dyes containing ester groups, of the formula <IMAGE> in which L denotes C1-C12-alkylene which is optionally substituted by phenyl, R<1> denotes C1-C12-alkyl, mono- or polyunsaturated C1-C12-alkenyl, which can be substituted by phenyl, C5-C7-cycloalkyl, C5-C7-cycloalkenyl, optionally substituted phenyl, pyrrolyl, furanyl, thienyl or pyridyl and R<2>, R<3>, R<4> and R<5> independently of one another denote hydrogen or optionally substituted C1-C12-alkyl, with the proviso that if R<5> denotes hydrogen, the ring positions of the substituents CH2-L-O-CO-R<1> and R<4> on one or both azulene rings can also be interchanged with one another within an azulene ring, their intermediates and an optical recording medium which contains the novel dyes. |
