Benzyl isocyanate → N-benzyl-N'-{4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl]-1,2,5-oxadiazol-3-yl}urea

Participants

Reaction Conditions

Reaction Steps

A solution of 3-(4-amino-1,2,5-oxadiazol-3-yl)-4-(3-bromo-4-fluorophenyl)-1,2,4-oxadiazol-5(4H)-one (30 mg, 88 μmol) and 4-dimethylaminopyridine (5 mg, 40 μmol) in pyridine (0.5 mL) was treated with benzyl isocyanate (29 mg, 0.2 mmol) and heated in the microwave at 150° C. for 20 min. The reaction mixture was concentrated and purified by preparative LCMS to give the intermediate N-benzyl-N′-{4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl]-1,2,5-oxadiazol-3-yl}urea. This material was diluted with ethanol (1.5 mL), treated with 2.0 M sodium hydroxide in water (0.3 mL), and stirred for 30 min. Purification of the crude reaction mixture by preparative HPLC gave the desired product (11 mg, 28%). LCMS for C17H15BrFN6O3 (M+H)+: m/z=448.9, 451.0.

Provenance & Evidence