Formaldehyde → 6,7-dihydro-4H-thieno[3,2-c]pyran

Participants

Reaction Steps

10.0 g of 2-thiopheneethanol, 5.9 g of paraformaldehyde, and 28.7 g of magnesium bromide were added to 780 mL of acetonitrile, and the resulting mixture was refluxed for 24 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. The organic layer was separated and dried over anhydrous magnesium sulfate, and then concentrated under reduced pressure. The residue was distilled under reduced pressure to obtain 4.7 g (yield of 43%) of the title compound, of which analysis data were the same as obtained in Example 14.

Provenance & Evidence