Lithium Hexamethyldisilazide → 1-(3-Ethoxy-4-methoxy-phenyl)-1-(3-nitro-4-methoxy-phenyl)-ethene

Participants

Reaction Steps

To a stirred suspension of triphenylmethylphosphonium bromide (1.8 g, 5.1 mmol) in THF (30 mL) in an ice bath was added lithium bis(trimethylsilyl)amide (1.0M solution in THF, 5.1 mL, 5.1 mmol) dropwise. The mixture was stirred at room temperature for 40 min. The Wittig reagent was then added slowly to a stirred suspension of (4-methoxy-3-nitro-phenyl)-(3-ethoxy-4-methoxy-phenyl)-methanone (1.4 g, 4.2 mmol) in THF (30 mL) in an ice bath. The mixture was stirred at room temperature for 5 hr. The mixture was poured into ice water (100 mL). The aqueous layer was extracted with methyl chloride (4×30 mL). The combined organic layers were washed with water (2×50 mL), brine (50 mL) and dried (MgSO4). Removal of solvent and chromatography (silica gel) gave 1-(3-ethoxy-4-methoxy-phenyl)-1-(3-nitro-4-methoxy-phenyl)-ethene as a solid (0.9 g, 67% yield): 1H NMR (CDCl3) δ 1.44 (t, J=7.2 Hz, 3H, CH3), 3.89 (s, 3H, OCH3), 3.98 (s, 3H, OCH3), 4.10 (q, J=7.0 Hz, 2H, OCH2), 5.37 (d, J=9.7 Hz, 2H, CH2), 6.83-6.84 (m, 3H, CH), 7.06(d, J=8.9 Hz, 1H, CH), 7.49-7.54 (dd, J=2.3, 8.9 Hz, 1H, CH), 7.84 (d, J=2.1 Hz, 1H, CH); 13C NMR (CDCl3) δ 14.70, 55.94, 56.56, 64.35, 111.19, 112.74, 113.10, 113.68, 120.80, 125.11, 133.08, 133.66, 134.27, 139.42, 147.24, 148.03, 149.49, 152.30.

Provenance & Evidence