Sodium Dithionite → 3-(4-aminophenyl)-4-oxo-4H-chromen-7-yl trifluoromethanesulfonate

Participants

Reaction Steps

To a suspension of 3-(4-nitrophenyl)-4-oxo-4H-chromen-7-yl trifluoromethanesulfonate (5.0 g, 14.75 mmol) in tetrahydrofuran (20 mL) was added a freshly prepared solution of sodium dithionite (5.13 g in 20 mL). The mixture was stirred at room temperature for 2 hours and then additional sodium dithionite (2.57 g) was added in two portions. The reaction mixture was stirred for 24 hours at room temperature, after which time the reaction was complete. The organic solvent was evaporated under reduced pressure and then water (10 mL) was added to the suspension. The solids in suspension were filtered off and dried under high vacuum. The product was heated with acetonitrile and stirred until room temperature was achieved. The solids were filtered off to provide 3-(4-aminophenyl)-4-oxo-4H-chromen-7-yl trifluoromethanesulfonate (4.1 g), which was used in the next step without further purification.

Provenance & Evidence