Pyridine → HCID 66686135, compound

Participants

Reaction Steps

2-Bromo-4-fluorobenzenesulfonyl chloride (0.229 g) was added to a solution of tert-butyl 7-amino-4-oxo-4H-furo[2,3-c]chromene-6-carboxylate (Intermediate 57, 0.210 g) and pyridine (1.13 mL) in DCM (20 mL) and the mixture was stirred at room temperature overnight. The mixture was reduced to half volume in vacuo and the resultant mixture was stirred and heated at 35° C. for 6 hours. Further 2-bromo-4-fluorobenzenesulfonyl chloride (0.572 g) was added and the reaction mixture was heated at 35° C. overnight. The mixture was evaporated to dryness and the residue was partitioned between water and ethyl acetate. The combined organic layers were dried (MgSO4), filtered and the filtrate was concentrated in vacuo. The residue was purified by chromatography on silica, eluting with ethyl acetate and cyclohexane, with a gradient of 5-20% to give tert-butyl 7-(2-bromo-4-fluorobenzenesulfonylamino)-4-oxo-4H-furo[2,3-c]chromene-6-carboxylate (0.329 g) as a white solid.

Provenance & Evidence