The starting material2,5-dimethyl-3-(3-methylphenylsulfanyl)-1-benzofuran was prepared byliterature method (Choi et al. 1999). 3-Chloroperoxybenzoic acid(77%,515 mg, 2.3 mmol) was added in small portions to a stirred solution of2,5-dimethyl-3-(3-methylphenylsulfanyl)-1-benzofuran (295 mg, 1.1 mmol)in dichloromethane (30 mL) at 273 K. After being stirred at room temperaturefor 8h, the mixture was washed with saturated sodium bicarbonate solution (2 X20 mL) and the organic layer was separated, dried over magnesium sulfate,filtered and concentrated at reduced pressure. The residue was purified bycolumn chromatography (hexane-ethyl acetate, 4:1 v/v) to affordthe title compound as a colorless solid [yield 73% (241 mg); m.p. 378-379 K;Rf = 0.43 (hexane-ethyl acetate, 4:1 v/v)]. Singlecrystals suitable for X-ray diffraction were prepared by slow evaporation ofa solution of the title compound (28 mg) in acetone (15 mL) at roomtemperature.
Molecules containing a benzofuran ring show interesting pharmacologicalproperties such as antibacterial and antifungal, antitumor and antiviral,antimicrobial activities (Aslam et al. 2009, Galal etal., 2009,Khan et al., 2005), and they are potential inhibitors ofβ-amyloidaggregation (Howlett et al., 1999, Ono et al.,2002). Thesebenzofuran compounds are widely occurring in nature (Akgul & Anil,2003;Soekamto et al., 2003). As a part of our ongoing program of3-arylsulfonyl-2,5-dimethyl-1-benzofuran derivatives containing4-methylphenylsulfonyl substituent in 3-position (Choi et al.,2013), we report herein on the crystal structure of the title compound.
2,5-Furandicarboxylic acid is a platform chemical for the production of biobased polymers and materials. This study reports the synthesis of furan oligoesters via polytransesterification of dimethyl furan-2,5-dicarboxylate and linear α, ω-aliphatic diols with chain length ranging from C2 to C12, using immobilized lipase B from Candida antarctica (Novozym 435) in dry organic solvents. Dimethyl furan-2,5-dicarboxylic acid (A) and 1,4-butanediol (B) were used as model substrates under different conditions producing a mixture of cyclic (CEOs) and linear (LEOs) ester oligomers up to decamers and dodecamers, respectively, with high yield. The size of the oligomers and distribution of the products is controlled by the initial concentration of substrates and temperature. While the shortest CEOs are the main cyclic compounds at 20 mM, the longest CEOs are formed at 175 mM. The chain length of the aliphatic diol co-monomers strongly influences the yield and the type of oligoesters formed. High substrate conversion of 90-95% was obtained for C4-C12 diols, while in the case of ethylene glycol and 1,3-propanediol the conversion was moderate (i.e., 75%). The product of the reaction between dimethyl furan-2,5-dicarboxylate and ethylene glycol (C2) and 1,3-propanediol (C3), respectively, consisted only of linear oligoesters. Longer oligoesters were obtained for alkyl chains higher than C4. The chain length and the abundance of oligoesters increases in the order: C2