Chloroform → 2-(4-t-Butylphenyl)-3-hydroxy-4-methylcarbonylthiophene

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Reaction Conditions

Reaction Steps

A chloroform (250 mL) solution of 2-(4-t-butylphenyl)-3-hydroxy-4-methylcarbonyl-2,5-dihydrothiophene (24.94 g, 64.6 mmol, purity: 78%) was cooled to −23° C., and to this solution, a chloroform (50 mL) solution of sulfuryl chloride (5.45 mL, 1.05 equivalent amounts) was dropwise added over a period of 27 minutes, followed by stirring at from −22 to −24° C. for 33 minutes. The temperature of the solution was raised to −3° C., and water (50 mL) was dropwise added over a period of 2.5 minutes, followed by liquid separation. The obtained chloroform solution was sequentially washed with water, a saturated salt solution, a sodium hydroxide aqueous solution, a saturated sodium thiosulfate aqueous solution and a saturated salt solution, and dried over anhydrous magnesium sulfate. The drying agent was removed by filtration, and the solvent was distilled off to obtain a crude product. The obtained crude product was distilled in chloroform (80 mL) at 45° C., the solution was cooled to 0° C., and isopropanol (375 mL) was dropwise added, followed by stirring at 0° C. for 40 minutes. The formed crystals were subjected to filtration to give the desired product as a yellow solid (15.5 g, yield: 63%).

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