1,1'-Carbonyldiimidazole → 4-(3-bromo-4-fluorophenyl)-3-(4-(2-methoxyethylamino)-1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazol-5(4H)-one

Participants

Reaction Conditions

Reaction Steps

A mixture of N-(3-bromo-4-fluorophenyl)-N′-hydroxy-4-[(2-methoxyethyl)amino]-1,2,5-oxadiazole-3-carboximidamide (76.5 g, 0.204 mol), 1,1′-carbonyldiimidazole (49.7 g, 0.307 mol), and ethyl acetate (720 mL) was heated to 60° C. and stirred for 20 min. LCMS indicated reaction completed. The reaction was cooled to room temperature, washed with 1N HCl (2×750 mL), dried over sodium sulfate, and concentrated to give the desired product (80.4 g, 98%) as a crude brown solid. LCMS for C13H12BrFN5O4 (M+H)+: m/z=400.0, 402.0. 1H NMR (400 MHz, DMSO-d6): δ 7.94 (t, J=8.2 Hz, 1 H), 7.72 (dd, J=9.1, 2.3 Hz, 1 H), 7.42 (m, 1 H), 6.42 (t, J=5.7 Hz, 1 H), 3.46 (t, J=5.4 Hz, 2 H), 3.36 (t, J=5.8 Hz, 2 H), 3.26 (s, 3 H).

Provenance & Evidence