1,2-Dichloroethane → 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 Conditions

Reaction Steps

A mixture of 3-(4-amino-1,2,5-oxadiazol-3-yl)-4-(3-bromo-4-fluorophenyl)-1,2,4-oxadiazol-5(4H)-one (68 mg, 0.20 mmol; from Step D) and ethyl {[(2,2-dimethoxyethyl)amino]sulfonyl}carbamate (154 mg, 0.600 mmol, 3.0 equiv.) in 1,2-dichloroethane (2.50 mL, 31.7 mmol) was stirred at 0° C. To this mixture was added trifluoroacetic acid (1.00 mL, 13.0 mmol) and triethylsilane (105 μL, 0.66 mmol, 3.3 equiv.)=drop-wise. The reaction mixture was stirred at 0° C. for 3 h. HPLC indicated 97.5% conversion to the desired product. The reaction mixture was cooled to 0° C. and quenched with saturated sodium bicarbonate to pH ˜8. The mixture was extracted in ethyl acetate (3×10 mL). The combined organic extracts were washed with brine, dried over sodium sulfate and concentrated. The residue was stirred in a mixture of heptane and diethyl ether overnight. The solids were collected by filtration, washed with heptane to give the desired product (95 mg, 88%) as a crude off-white solid. 1H NMR (300 MHz, DMSO-d6) δ 11.18 (s, 1H), 8.08 (m, 1H), 7.70 (m, 2H), 7.59 (t, 1H, J=8.7 Hz), 6.56 (s, 1H), 4.04 (d, 2H, J=7.2 Hz), 3.35 (m, 2H), 3.11 (m, 2H), 1.15 (t, 3H, J=7.2 Hz); C15H15BrFN7O7S (MW 536.29), LCMS (EI) m/e 536/538 (M++H).

Provenance & Evidence