Sodium Hydroxide → 4-amino-2-fluoro-N-(1-hydroxy-1,3-dihydrobenzo[c][1,2]oxaborol-6-yl)benzenesulfonamide

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Reaction Steps

A solution of N-(3-fluoro-4-(N-(1-hydroxy-1,3-dihydrobenzo[c][1,2]oxaborol-6-yl)sulfamoyl)phenyl)acetamide (1.45 g, 3.98 mmol) in 1,4-dioxane (8 mL) and concentrated hydrochloric acid (2 mL) was refluxed at 100° C. for three hours. The solution was cooled to room temperature and neutralized to pH 5 using 3 N sodium hydroxide. The solution was extracted using ethyl acetate and water. The organic layer was washed three times with water, than washed with brine, dried over sodium sulfate, and filtered. The solvent was removed under reduced pressure. The residue was purified by silica column via CombiFlash using dichloromethane and methanol. The desired fractions were collected and the solvent was removed under reduced pressure. Water and toluene were added and removed under reduced pressure. Diisopropyl ether was used to transfer powder from round bottom flask to Buckner funnel to give 4-amino-2-fluoro-N-(1-hydroxy-1,3-dihydrobenzo[c][1,2]oxaborol-6-yl)benzenesulfonamide (0.176 g, 14% yield). 1H NMR (400 MHz, DMSO-d6) δ (ppm) 4.85 (s, 2H), 6.23-6.31 (m, 4H), 7.16 (dd, J=2.1 Hz, J=8.1 Hz, 1H), 7.22 (d, J=8.3 Hz, 1H), 7.36 (t, J=8.6 Hz, 1H), 7.43 (d, J=1.8 Hz, 1H), 9.17 (s, 1H), 10.06 (s, 1H).

Provenance & Evidence