6,7-HETEROANNEALED 2,2-DIPHENYL CHROMENES AND USE THEREOF IN OPHTHALMIC OPTICS

摘要

Photochromic compounds of general formula (I), wherein R<a>, R<b> and R<c> are hydrogen; alkyl; OR, SR, COR or COOR, where R is hydrogen, alkyl or aryl, amino of formula NR1R2 where R1 and R2 are hydrogen, alkyl, cycloalkyl, aryl, or R1 and R2 together with the nitrogen atom form a 4- to 7-membered heterocyclic ring and optionally also contain one or more heteroatoms selected from nitrogen, oxygen, sulphur, a halogen atom and a mono or polyhaloalkyl grouping; an NO2, CN or SCN grouping; n and m are integers from 1 to 5 depending on the number of substitutions on the nucleus; H is a 5-membered aromatic heterocyclic ring comprising one or more heteroatoms selected from nitrogen, selenium, oxygen and sulphur; said heterocyclic ring being optionally substituted by one or more alkyl, alkoxy, amino, aryl or aralkyl groupings or groupings fused with an aromatic nucleus; and the use thereof in ophthalmic optics.