Sodium Carbonate → 4-(3-Cyclopentyloxy-4-methoxyphenyl)-4-(3-aminophenylethynyl)cyclohexan-1-one

Beteiligte Stoffe

Reaktionsschritte

To 4-(3-cyclopentyloxy-4-methoxyphenyl)-1,1-(ethylenedioxy)-4-(3-nitrophenylethynyl)cyclohexane (0.17 g, 0.35 mmol) in methanol (1 mL), acetic acid (1.2 mL) and water (1.2 mL) under an argon atmosphere was added titanium trichloride (0.3 g, 2 mmol). After stirring for 1.5 h at room temperature, titanium trichloride (0.3g, 2 mmol) and water (1.2 mL) were added, and the mixture was stirred for 0.5 h at room temperature and for 0.5 h at 45°-50°C., then was cooled to room temperature. Water (1.2 mL) and ammonium hydroxide (2.5 mL) were added. After stiinng an additional 1 h, methanol (17.5 mL), 5% sodium carbonate (17.5 mL) and dichloromethane (35 mL) were added, and stirring was continued for 2 h. The suspension was filtered through Celite®, was washed well with dichloromethane and the extract was evaporated. The residue was diluted with dichloromethane, the organic layer was washed with 5:95 ammonium hydroxide:water, was dried (potassium carbonate) and was evaporated. Purification by flash chromatography, eluting with 3:7 ethyl acetate:hexanes, provided a mixture of 4-(3-cyclopentyloxy-4-methoxyphenyl)-4-(3-anminophenylethynyl)-cyclohexan-1-one and 4-(3-cyclopentyloxy-4-methoxyphenyl)-1,1-(ethylenedioxy)-4-(3-aminophenylethynyl)cyclohexane (0.07 g). This mixture and a spatula-tip of pyridinium p-toluenesulfonate in acetone (4 mL) and water (1 mL) was refluxed for 3 days, then was evaporated. Water was added, the mixture was extracted three times with dichloromethane, the extract was dried (magnesium sulfate) and was evaporated. Purification by flash chromatography, eluting with 35:65 ethyl acetate:hexanes provided 4-(3-cyclopentyloxy-4-methoxyphenyl)-4-(3-aminophenylethynyl)cyclohexan-1-one as a colorless oil. 1H-NMR (400 MHz, CDCl3) δ 7.22 (d, J=2.2 Hz, 1H), 7.14 (m, 2H), 6.87 (m, 2H), 6.82 (d, J=2.8 Hz, 1H), 6.66 (dd, J=9.0, 2.4 Hz, 1H), 4.81 m, 1H), 3.85 (s, 3H), 3.7 (br, 2H), 3.04 (dt, J=14.3, 6.0 Hz, 2H), 2.47 (br d, J=14.6 Hz, 2H), 2.2-2.3 (m, 4), 1.8-2.0 (m, 6H), 1.61 (m, 2H).

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