| 摘要 |
PROBLEM TO BE SOLVED: To provide a preparation process which can produce in high yields a pyrromethene dyestuff comprising an α,α-pyrromethene boron complex that contains a condensed aromatic ring. SOLUTION: There is provided a process for preparing a pyrromethene dyestuff, which comprises heating an α,α-pyrromethene boron complex containing a condensed bicyclo ring, represented by formula (I): wherein R1 is a hydrogen atom, alkyl group, aryl group or heterocyclic group; R2 and R3 are each independently a halogen atom, alkyl group, aryl group or heterocyclic group; the pyrrole rings may have substituting group(s); and the ring X is a condensed bicyclo ring formed by linking, with each other, two β-positioned substituting groups of at least one pyrrole ring to form an α,α-pyrromethene boron complex containing a condensed aromatic ring, represented by formula (II): wherein R1, R2 and R3 each has the same meaning as those in formula (I); the pyrrole rings may have substituting group(s); and the ring Y is a condensed aromatic ring formed at the two β-positions of at least one pyrrole ring. |
