Synthesis and Photochromism of Novel Pyridyl-Substituted Naphthopyrans.

Multitarget synthetic strategies to access novel photochromic 3-naphtho[2,1-]pyrans decorated with pyridyl units are described. The new pyridyl-substituted 3-naphtho[2,1-]pyrans display good photochromic properties with reversible generation of photomerocyanines, which exhibit mainly orange/red hues. Photochromic parameters including photocolorability and persistence of color vary tremendously on structural modification of the naphthopyran core.