Triethylamine → 2-[[4-[4-(3-Bromo-4-fluorophenyl)-5-oxo-1,2,4-oxadiazol-3-yl]-1,2,5-oxadiazol-3-yl]amino]ethyl methanesulfonate

Participants

Reaction Steps

4-(3-bromo-4-fluorophenyl)-3-(4-(2-hydroxyethylamino)-1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazol-5(4H)-one (72.2 g, 0.188 mol) was mixed with ethyl acetate (600 mL). Methanesulfonyl chloride (19.2 mL, 0.248 mol) was added followed by triethylamine (34.9 mL, 0.250 mol). The reaction was stirred at room temperature for 5 min. When LCMS indicated completion of reaction (M+H=442), 500 mL of water was added into reaction. The reaction was extracted with ethyl acetate (2×500 mL). The combined ethyl acetate solution was washed with brine (500 mL), dried over sodium sulfate and concentrated to give 85.1 g crude brown solid. 1H NMR verified the structure. Crude yield was 97%. LCMS for C13H11BrFN5O6SNa (M+Na)+: m/z=485.9, 487.9. 1H NMR (400 MHz, DMSO-d6): δ 8.08 (dd, J=6.2, 2.5 Hz, 1 H), 7.72 (m, 1 H), 7.58 (t, J=8.7 Hz, 1 H), 6.75 (t, J=5.9 Hz, 1 H), 4.36 (t, J=5.3 Hz, 2 H), 3.58 (dd, J=11.2, 5.6 Hz, 2 H), 3.18 (s, 3 H).

Provenance & Evidence