indium(III)chloride → 6,7-dihydro-4H-thieno[3,2-c]pyran

Participants

Reaction Steps

11.0 g of 2-[2-(2-methoxyethoxymethoxy)ethyl]thiophene obtained in Example 20 and 1.1 g of indium(III) chloride were added to 750 mL of acetonitrile, and the resulting mixture was refluxed for 5 hours. The reaction product solution was cooled to room temperature and concentrated by evaporation under reduced pressure. To the residue, 100 mL of water and 150 mL of n-hexane were added, and the resulting mixture was stirred for 5 minutes. Aqueous layer was discarded, and the organic layer was washed twice with 70 mL portions of water, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was distilled under reduced pressure to obtain 2.9 g (yield of 41%) of the title compound, of which analysis data were the same as obtained in Example 14.

Provenance & Evidence