Hydrochloric Acid → HCID 18314014, compound

Participants

Reaction Steps

To a suspension containing 60% sodium hydride (0.64 g, 15.9 mmol) and ethyl acetate (8.16 g, 92.9 mmol) in tetrahydrofuran (5 ml) were added in turn at room temperature a solution containing ethyl 4-acetyl-3-methyl-5-(methylthio)thiophene-2-carboxylate (2.0 g, 7.7 mmol) and ethanol (0.5 ml) in tetrahydrofuran (10 ml) and a solution containing dibenzo-18-crown-6 ether (0.04 mg) in tetrahydrofuran (5 ml), and the mixture was heated under reflux for 2 hours. The reaction solution was allowed to cool down to room temperature, made acidic by addition of 3N hydrochloric acid and extracted with ethyl acetate. The organic layer was washed (with water and saturated aqueous sodium chloride, in turn), dried (over anhydrous magnesium sulfate) and concentrated under reduced pressure. The residue thus obtained was purified by silica gel column chromatography (developing solvent: n-hexane/ethyl acetate=20:1) to afford ethyl 3-methyl-5-methylthio-4-(3-oxobutyryl)thiophene-2-carboxylate (1.91 g, 82%) as yellow -crystals.

Provenance & Evidence