Hydrochloric Acid → HCID 89714569, compound

Participants

Reaction Conditions

Reaction Steps

5 g of 4-amino-3-fluorophenylboronic acid pinacol ester (21.08 mmol) are placed in 100 ml of DCM. 3.23 ml of triethylamine (23.20 mmol) are added. The reaction mixture is cooled in an ice bath to 4° C. After stirring for 5 minutes, 2.21 g of triphosgene (7.38 mmol) are added portionwise, and the ice bath is then removed. After stirring for 1 hour 30 minutes at room temperature, 8.77 g of ethylamine hydrochloride (105.45 mmol) and then 14.57 g of K2CO3 (105.45 mmol) are added portionwise. After 2 hours, the medium is cooled in an ice bath and then acidified with 1 N hydrochloric acid solution. The aqueous phase is extracted 3 times with DCM. The organic phases are combined, washed with brine, dried over MgSO4, filtered and concentrated. The residue is chromatographed on silica gel with a gradient of from 0% to 5% MeOH in DCM to give 4.65 g of 1-ethyl-3-[2-fluoro-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)phenyl]urea.

Provenance & Evidence