Water → 1,2-Bis(2-methyl-6-formyl-1-benzothiophen-3-yl)cyclopentene

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Reaction Conditions

Reaction Steps

Dichloromethyl ether (4.52 ml, 50 mmol) and anhydrous aluminum chloride (1.78 g, 13.35 mmol) were added to a stirred solution of 1,2-bis(2-methyl-1-benzothiophen-3-yl)cyclopentene 4 (1.2 g, 3.33 mmol) in nitrobenzene (25 ml) at 0° C., and the mixture was stirred for 30 min at 0° C. and for 20 hours at room temperature. The reaction mixture was poured into icy water, and the product was extracted by ethyl acetate, was washed with water and was dried by magnesium sulfate. After distillation of nitrobenzene under vacuum, the product was purified by the column chromatography (Silica Gel, 0.063-0.1) with a petroleum ether (40/70):ethyl acetate mixture (6:1 by volume) being used as an eluent. The yield was 0.56 g of dialdehyde 5 (40%), Tmelt=196-197° C. (hexane:chloroform, 6:1 by volume). Mass spectrum, m/z: 416, [M]+. A 1H NMR spectrum (DMSO-d6, δ, ppm, J/Hz): 2.25 (m, 6H, 2×CH3), 2.97 (br m, 6H, 3×CH2), 7.6-8.5 (br m, 6H, CHarom.), 9.98 (br m, 2H, 2×CHO). The results found (%): C, 72.16; H, 4.86; S, 15.34. C25H20O2S2. The results calculated (%): C, 72.08; H, 4.84; S, 15.40.

Provenance & Evidence