To a solution of hydroxylamine hydrochloride (816 mg, 12 mmol) in anhydrous acetonitrile (35 mL), were added triethylamine (1.6 ml, 12 mmol), and 2-[1-(triphenylmethyl)imidazol-4-yl]cyclopropanecarbaldehyde (4.0 g, 11 mmol) The resulting mixture was stirred for about 2 hours followed by the addition of phthalic anhydride (1.6 g, 11 mmol) under nitrogen. Then the reaction mixture was heated under reflux for 8 hours, concentrated under reduced pressure, diluted with 5% aqueous ammonia (30 mL), and extracted with ethyl acetate (3×40 ml). The organic layer was dried with MgSO4, and then evaporated under reduced pressure. The resulting residue was purified on a silica gel column using ethyl acetate/hexane (v/v:1/6) as the eluting solvent to give the title compound as a pale yellow solid (2.4 g, 64% yield).
