Synthesis and photochromism of spiroindoline-2,2'-pyrano[2,3-f]coumarins

Indoline spiropyrans containing a formylcoumarin moiety annulated to the 2H-pyran ring at the 6,5-position have been synthesized, and their structure and photochromism have been studied. It has been shown that the synthesized compounds exhibit better spectral-kinetic and photochromic properties as compared with other coumarin spiropyrans.