反应详情

A mixture of methyl 2-butyl-4-chloro-1-(4-nitrobenzyl)imidazole-5-acetate (5.00 g, 13.7 mmol, 1 eq), iron (2.67 g, 47.8 mmol, 3.5 eq), glacial acetic acid (5.47 mL, 95.3 mmol, 7 eq), and methanol (250 mL) was refluxed for 5.5 hours. The solvent was removed by rotary evaporation. The residue was diluted with water (300 mL) and extracted five times with 300 mL portions of ethyl acetate. The organic layers were dried and concentrated. The residue was flash chromatographed in 75:25 hexane/ethyl acetate over silica gel to give 4.53 g of a golden yellow oil which crystallized after standing for several days. NMR (200 MHz, CDCl3) δ 6.72 (d, 2H, J=7 Hz); 6.60 (d, 2H, J=7 Hz); 4.99 (s, 2H); 3.61 (s, 3H); 3.47 (s, 2H); 2.60 (t, 2H, J=7 Hz); 1.68 (m, 2H); 1.35 (m, 2H); 0.86 (t, 3H, J=7 Hz). Mass spectrum shows M+=355/337. Mass Calcd. for C17H22N3O2Cl: 335.1400. Found: 335.1407.

1. temperaturewas refluxed for 5.5 hours
2. customThe solvent was removed by rotary evaporation
3. additionThe residue was diluted with water (300 mL)
4. extractionextracted five times with 300 mL portions of ethyl acetate
5. customThe organic layers were dried
6. concentrationconcentrated
7. customchromatographed in 75:25 hexane/ethyl acetate over silica gel