Acetic Acid → N-[2-({4-[4-(3-Bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl]-1,2,5-oxadiazol-3-yl}amino)ethyl]sulfamide

Participants

Reaction Steps

A solution of 2,2,2-trichloroethyl ({[2-({4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl]-1,2,5-oxadiazol-3-yl}amino)ethyl]amino}sulfonyl)carbamate (320 mg, 0.50 mmol; from Step Q, Method D) in tetrahydrofuran (THF, 4.0 mL) was stirred at room temperature. Acetic acid (0.30 mL, 5.3 mmol) and zinc flakes (160 mg, 2.5 mmol, 5.0 equiv.) were sequentially added. This reaction mixture was stirred at room temperature for 3 h. HPLC indicated reaction completion. The reaction mixture was filtered through Celite and the Celite was washed with THF. The combined filtrate was concentrated in vacuum and the resulting residue was dissolved in ethyl acetate (20 mL). The ethyl acetate solution was washed with saturated sodium carbonate and brine, dried over sodium sulfate and concentrated. The crude material was crystallized from ethyl acetate and diethyl ether to give the desired product (147 mg, 63%) as an off-white solid.

Provenance & Evidence