Synthesis Of Indolyl Substituted Fulgides

Since it was discovered that some solid or liquid compounds have photochromic properties, a variety of photosensitive materials has aroused great research interests. Indolyl Substituted fulgides showed good fatigue resistance, thermal stability and can display excellent photochromic properties in different media, thus they will have potential applications in the preparation of photochromic textiles and clothing materials.In this research work, a series of indolyl substituted fulgides were prepared by the Stobbe condensation reaction of isopropylidene diethyl succinate with formyl or acetyl indole derivatives. The formyl or acetyl indole derivatives were prepared via Vilsmeier-Haack reaction of substitited indoles with DMF or DMA and N-Alkylation of substitited indoles with alkylating reagents. All intermediates were characterized by melting point mearsurement and/or 1H NMR, 13C NMR and EI (ESI)-MS. (E)-3-((1-(2-methoxyethyl)-3-methyl-1H-indol-2-yl) methylene)-4-(propan-2-ylidene)-dihydrofuran-2,5-dione was reported in the first time in this work. The E-form was the only stable form. The configuration would change from E-form (light yellow) to C-form (violet-red) under UV-Vis irradiation. The thermal stability and photochromic properties of this compound were studied by UV-Vis and TG-DTA. The results showed this compound had good thermal stability and photochromic properties.