Sodium;azanide;methyl(triphenyl)phosphanium;bromide → 1-(3,3-dimethyl-indan-1-yl)-5-vinyl-1H-imidazole

Participants

Reaction Steps

To a solution of methyltriphenylphosphonium bromide/sodium amide [2.4 mmol/gram of salt (0.86 g, 2.06 mmol)] in THF (3.0 mL) is added a solution of 3-(3,3-dimethyl-indan-1-yl)-3H-imidazole-4-carbaldehyde (165 mg, 0.69 mmol) in THF (2 mL). The reaction is permitted to stir at room temperature for 30 minutes and is then quenched with saturated aqueous NH4Cl. The reaction is diluted with ethyl acetate and the layers are separated. The aqueous layer is extracted with ethyl acetate and the organic layers are combined, dried with Na2SO4, filtered, and concentrated. The resulting residue is purified by silica gel flash chromatography (ethyl acetate-dichloromethane, 0:1 to 1:4) to furnish semi-pure 1-(3,3-dimethyl-indan-1-yl)-5-vinyl-1H-imidazole. Further purification via semi-preparative reverse phase HPLC (5 to 100% acetonitrile/water w/0.1% NH4OH), affords 1-(3,3-dimethyl-indan-1-yl)-5-vinyl-1H-imidazole; MS: (ESI) m/z 239 (M+H)+; 1H NMR (400 MHz, CDCl3) δ ppm 1.29 (s, 3 H), 1.39 (s, 3 H), 2.11 (dd, J=13.0, 7.7 Hz, 1 H), 2.54 (dd, J=12.9, 7.8 Hz, 1 H), 5.20 (dd, J=11.4, 1.3 Hz, 1 H), 5.62 (dd, J=17.4, 1.3 Hz, 1 H), 5.72 (t, J=7.7 Hz, 1 H), 6.42 (dd, J=17.4, 11.1 Hz, 1 H), 7.09 (dd, J=7.6, 0.8 Hz, 1 H), 7.23-7.30 (m, 3 H), 7.32 (s, 1 H), 7.37 (t, J=7.5 Hz, 1 H). The HCl salt of the title compound can be prepared by dissolution in diethyl ether, followed by treatment with an excess of 1N HCl in diethyl ether. The resulting heterogeneous solution is concentrated to furnish the HCl salt of 1-(3,3-dimethyl-indan-1-yl)-5-vinyl-1H-imidazole.

Provenance & Evidence