Triethylamine → 2-Acetyl-4,5-dihydro-6,8-dimethylnaphtho[1,2-b]thiophene

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Reaction Steps

Next, 1.4 mL of triethylamine was added dropwise to a 10 mL ethanol solution of 0.9 g of 2,5-dihydroxy-2,5-dimethyl-1,4-dithiane, and the system was stirred for 30 minutes at room temperature. To this was added at room temperature a 10 mL ethanol solution of the 1-chloro-2-formyl-3,4-dihydronaphthalene obtained previously, and the system was refluxed under heating overnight. After the reaction, reduced-pressure solvent distillation was performed, first water and then 2M a sodium hydroxide aqueous solution were added under ice cooling, and extraction was performed with ethyl acetate. The organic layer was washed first with a saturated ammonium chloride aqueous solution and then with saturated brine, dried with magnesium sulfate, and subjected to reduced-pressure solvent distillation, and the residue was refined by silica gel column chromatography (20% ethyl acetate/hexane) and then recrystallized with ethanol to obtain 1.6 g of 2-acetyl-4,5-dihydro-6,8-dimethylnaphtho[1,2-b]thiophene (Table 6-1) in the form of yellow crystals.

Provenance & Evidence