To obtain a pyrrole compound having good recording characteristics and useful for optical recording media excellent in light resistance.
This bispyrrole compound is expressed by formula I (R1 is H, an alkyl; R2-R6 are each H, an alkyl, an alkoxy, an alkylcarbonyl, a halogen, etc.; X- is an anion). The compound of formula I is obtained by condensing a pyrrole compound of formula II with a 1,3-cyclohexanedione of formula III in the presence of an inorganic acid catalyst (e.g. HBF4) and then substituting the anion of the inorganic acid by one of other various anions. The addition of the bispyrrole compound of formula I to recording layers gives optical recording media enabling the recording and regeneration of information or the regeneration of information with light having a wavelength selected from among 620-690nm and further enabling the recording and regeneration of information or the regeneration of information on the basis of the CD standard with light having a wavelength selected from among 770-830nm.
MISAWA TSUTAYOSHI
SUGIMOTO KENICHI
TSUDA TAKESHI
UMEHARA HIDEKI
TAKUMA HIROSUKE
