Potassium Carbonate → 3-(5,6,7,8-Tetrahydro-naphthalen-1-yloxy)-but-2-enoic acid ethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 5,6,7,8-tetrahydro-naphthalen-1-ol (3.00 g, 20.24 mmol) and ethyl-2-butynoate (13.62 g, 121.46 mmol) in tetrahydrofuran (100 mL) was treated with potassium carbonate (3.10 g, 22.43 mmol) and 4-dimethylaminopyridine (0.26 g, 2.12 mmol). The reaction was then heated at 85° C. overnight. At this time, the reaction was cooled to 25° C. and was stirred at 25° C. overnight. At this time, the reaction was concentrated in vacuo. The residue was dissolved in ethyl acetate (200 mL) and was washed with water (1×100 mL) and a saturated aqueous sodium chloride solution (1×100 mL). The organics were then dried over magnesium sulfate, filtered, rinsed with ethyl acetate and concentrated in vacuo. The material was taken up in ethyl acetate and absorbed onto silica gel. Purification by Analogix flash chromatography (115 g, 1-10% ethyl acetate/hexanes) afforded 3-(5,6,7,8-tetrahydro-naphthalen-1-yloxy)-but-2-enoic acid ethyl ester (3.82 g, 72%) as a light yellow oil: HR-ES-MS m/z calculated for C26H34N4O5 [M+H]+ 483.2602, observed 483.2603; 1H NMR (400 MHz, DMSO-d6) δ ppm 1.11 (t, J=7.1 Hz, 3H), 1.61-1.77 (m, 4H), 2.44 (s, 3H), 2.46 (br. s., 2H), 2.76 (br. s., 2H), 3.98 (q, J=7.1 Hz, 2H), 4.57 (s, 1H), 6.84 (d, J=7.7 Hz, 1H), 7.03 (d, J=7.7 Hz, 1H), 7.18 (t, J=7.7 Hz, 1H).

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