Лако-красочные материалы — производство

One further example of this principle of bridging the aryl groups of a triarylmethane phthalide was reported in 1986.108 Thus, treatment of phthalide 27 with aluminum chloride results in the formation of the spirobenzanthracene 28 as shown in Scheme 11. These color formers also exhibit absorption in the near infrared spectral region, but no further reports of such compounds have since been published.