5,5′‐Isopropylidene‐bis(ethyl 2‐furoate), a monomer prepared from bio‐based ethyl 2‐furoate, was reacted with dimethyl terephthalate and ethan‐1,2‐diol (ED) by melt polycondensation in order to obtain copolyesters containing both terephthalate and furoate units. The conventional two‐step method involving (i) the formation of a hydroxyethyl‐terminated oligomer by reaction of starting diester mixture with excess ED and (ii) a polycondensation step with elimination of ED was used to obtain high molar mass copolyesters. Copolymers of various compositions were synthesized and characterized by 1H NMR, DSC, and TGA. For all compositions, the degree of randomness, determined by 1H NMR, was close to 1, reflecting a random distribution of terephthalic and furanic ester units in polymer chains. The resulting materials are amorphous polymers (Tg = 70–80 °C) with good thermal stability.
An efficient and environmentally benign synthesis of 3‐organoselenylchromenones was accomplished via iron(III) chloride/diorganyl diselenides‐promoted intramolecular 6‐endo‐dig cyclization of alkynyl aryl ketone derivatives. The cyclization reactions proceeded cleanly under mild reaction conditions, and the desired chromenone derivatives were smoothly isolated in good yields. The methodology proved to be highly regioselective, giving only the six‐membered regioisomers and was carried out using iron(III) chloride/diorganyl diselenide at room temperature and under ambient atmosphere, which could be considered an economic and eco‐friendly protocol.
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