A solution of (S)-tert-butyl 2-(4-aminophenyl)morpholine-4-carboxylate (140 mg, 0.5 mol), 4-fluoro-N-(methylsulfonyloxy)benzimidoyl chloride (152 mg, 0.6 mmol) and N,N,N′,N′-tetramethylethylenediamine (123 mg, 1.06 mmol) in tetrahydrofurane (0.8 ml) was shaken in a closed vial at 60° C. overnight. Water was added, and the mixture was extracted twice with ethyl acetate. The cobined organic layers were dried (MgSO4) and evaporated. Flash chromatography (10 g silica gel, 10 to 30% ethyl acetate in heptane) yielded a white solid (92 mg, 46%), MS (ISP): 398.2 ([M+H]+).
