Preparation of cyanine dye for high density optical recording disk

摘要

A cyanine dye for using in high density optical disc recording medium, having the following structure: wherein R represents 4-methoxycarbonyl benzyl group, X- represents an acid anion, and n represents an integer of 1 or 2. This cyanine dye is suitable for use as a lambda =450 nm DIFFERENCE 650 nm visible light-absorbing organic dye useful as a high density optical disc recording medium.