To a solution of but-3-enyl-(3-fluoro-6-nitro-2-vinylphenyl)amine (327.6 mg, 1.386 mmol) in DCM (30 mL) was added Grubbs catalyst (2nd generation, benzylidene[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(tricyclohexylphosphine)ruthenium) (47 mg, 0.055 mmol). The reaction mixture was stirred at RT for 16 h, and then a further portion of the Grubbs catalyst (47 mg, 0.055 mmol) was added and stirring continued for a further 64 h. The reaction mixture was concentrated in vacuo and then purified by column chromatography (Si—PCC, eluant 2-6% EtOAc in cyclohexane). The recovered starting material (145 mg) was dissolved in DCM (20 mL) and Grubbs 2nd generation catalyst (30 mg, 0.035 mmol) was added. The reaction mixture was heated under reflux for 6 h, then left at RT for 16 h. The reaction mixture was concentrated in vacuo, combined with the product from the initial purification and purified by column chromatography (Si—PCC, eluant 2-8% EtOAc in cyclohexane) affording the title compound as a red solid (225.4 mg, 78%). 1H NMR (CDCl3, 300 MHz): 8.90 (1H, bs), 8.09 (1H, dd, J=9.4, 6.0 Hz), 6.67 (1H, dt, J=12.3, 1.8 Hz), 6.47 (1H, t, J=9.6 Hz), 6.16 (1H, dt, J=12.3, 4.7 Hz), 3.52 (2H, q, J=4.9 Hz), 2.65 (2H, dq, J=4.8, 1.8 Hz)
