Boron tribromide → HCID 58934952, compound

Participants

Reaction Steps

To a solution of 6.8 g (20.6 mmol) of ethyl 6-ethyl-7-methoxy-2-(trifluoromethyl)-2H-chromene-3-carboxylate in 30 mL of anhydrous DCM at −78° C. in dry ice/acetone bath was added dropwise a solution of 206 ml (1.0 M in DCM, 206 mmol) of boron tribromide. After finishing addition, the dry ice/acetone bath was removed. The reaction was stirred at room temperature overnight. The reaction was cooled back to −78° C. in dry ice/acetone bath and treated dropwise with 250 mL of methanol. The reaction was allowed to warm to room temperature and subsequently concd in vacuo. The residue was purified by silica chromatography with EtOAc/hexane (2:8). The collected fractions were concd and used directly in step 3.

Provenance & Evidence