A solution of [3-(isopropyl-hydrazono)-propyl]-carbamic acid benzyl ester (60.0 mg, 0.228 mmol) and 2-[3-(4-fluoro-phenyl)-2-nitro-allyl]-[1,3]dioxolane (54.0 mg, 0.213 mmol) in THF (2 mL) was stirred at rt for 3 days. The mixture was treated with additional [3-(isopropyl-hydrazono)-propyl]-carbamic acid benzyl ester (1.4 equiv.) and was stirred at 60° C. for 18 h. Additional [3-(isopropyl-hydrazono)-propyl]-carbamic acid benzyl ester (2.1 equiv.) was added, and the mixture was stirred at 60° C. for 18 h. The mixture was concentrated to oil and the residue was purified by FCC to give the title compound.
