Hydrochloric Acid → 4-(5-Bromo-6-methoxy-2-naphthyl)-4-hydroxybut-3-en-2-one

Beteiligte Stoffe

Reaktionsschritte

139.4 Grams (0.499 moles) of 2-acetyl-5-bromo-6-methoxynaphthalene and 1450 ml of ethyl acetate are placed in a flask equipped with refrigerator and stirrer and, under stirring and at the temperature of 45° C., 30 g (0.556 moles) of sodium methoxide are added. The temperature of the reaction mixture goes up to 55° C. and is kept at 65° C. for one hour, then other 10 g (0.185 moles) of sodium methoxide are added and, after half an hour, still other 10 g (0.185 moles) of sodium methoxide, always under stirring and keeping the temperature at 65° C. for another hour and half. The reaction mixture is then cooled to room temperature and brought to pH 4 by adding a concentrated aqueous solution of hydrochloric acid. The reaction mixture is then heated to reflux for 15 minutes, cooled to 5° C. in one hour and kept at this temperature for 2 hours. The precipitated solid is filtered, abundantly washed with water on the filter, then washed with ethyl acetate and dried in oven under vacuum obtaining 145.7 g of product with a yield equal to 90.8%.

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