反应详情

A mixture of 1.2 g of 1-(4-nitrobenzyl)-2-butyl-4-chloroimidazole-5-aldehyde and 1.5 g of (carboxymethylene)triphenylphosphorane in 50 mL of benzene was refluxed for 2 hours. The reaction mixture was concentrated and the residue was purified by flash column chromatography on silica gel (Hexane:EtOAc=3:1 elution). The major product, the E isomer, was eluted first and was obtained as a thick oil initially which solidified to give an amorphous solid, 1.2 g. The minor product, the Z isomer was eluted next and was isolated as a thick liquid, 85 mg. E isomer: NMR (200 MHz, CDCl3): 7.3 and 6.53 (d, 2H, 5=16 Hz); 5.3 (s, 2H); 2.62 (t, 2H, J=7.3 Hz); 1.69 (m, 2H); 1.28 (m, 5H); 0.89 (t, 3H, J=7.3 Hz). Z isomer: NMR (200 MHz, CDCl3): (key peaks only) δ6.45 and 6.02 (d, 2H, J=11.8 Hz); 5.17 (s, 2H).

1. temperaturewas refluxed for 2 hours
2. concentrationThe reaction mixture was concentrated
3. customthe residue was purified by flash column chromatography on silica gel (Hexane:EtOAc=3:1 elution)
4. washThe major product, the E isomer, was eluted first
5. customwas obtained as a thick oil initially which
6. customto give an amorphous solid, 1.2 g
7. washThe minor product, the Z isomer was eluted next
8. customwas isolated as a thick liquid, 85 mg