A cyclic merocyanine UV-A absorber: mechanism of formation and crystal structure

The product of the reaction of 3-(3-methoxypropylamino)cyclohex-2-en-1-one and diethylsulfate has been crystallized and its structure has been determined by X-ray crystallography. The study allowed insight into the formation mechanism of cyclic merocyanine UV absorbers. X-ray diffraction analysis of the merocyanine product made it possible to define the E/Z-stereoconfiguration. (C) 2014 Elsevier Ltd. All rights reserved.