The Synthesis and Characterization of Solvatochromic Maleimide-Fused N-Allyl- and N-Alkyl-Substituted 1,4-Dithiines and Diels-Alder Reactions with Anthracene

A simple and facile access to new solvatochromic maleimide-fused N-allyl- and N-alkyl-substituted 1,4-dithiines from the corresponding N-substituted succinamic acid derivatives in one-pot with oxidation by thionyl chloride is described. The Diels-Alder reaction of these 1,4-dithiines with anthracene has been investigated. The 1,4-dithiine derivatives react smoothly with anthracene via charge-transfer complexes to form the Diels-Alder adducts in excellent yields.