Ethyl 2-bromopropionate → HCID 14721691、化合物

In 100 ml of ethanol was dissolved 10.0 g. (0.05 mole) of sodium 2,4-dichloro-3-methylphenolate. With stirring at room temperature, 9.1 g (0.05 mole) of ethyl 2-bromopropionate was added. The mixture was heated under relfux for 4 hours. The ethanol was distilled off under reduced pressure, and the residue was extracted with 50 ml of diethyl ether. The ethereal layer was washed with 25 ml of a 5% aqueous solution of sodium hydroxide and 25 ml of water, and dried over anyhdrous magnesium sulfate. The dessicant was removed by filtration, and the diethyl ether was distilled off to give 11.8 g of crude ethyl 2-(2,4-dichloro-3-methylphenoxy)propionate. The crude ester (11.8 g) was dissolved in 100 ml of glacial acetic acid. Concentrated hydrochloric acid (25 ml) was added, and the mixture was stirred at 100° C. for 40 minutes. The reaction mixture was cooled, and poured onto 300 ml of ice water. The precipitated crystals were filtered, washed with water, and dried to give 9.2 g of 2-(2,4-dichloro-3-methylphenoxy)-propionic acid. The yield was 73.9% based on the sodium 2,4-dichloro-3-methylphenolate, and the final product had a melting point of 149.5 to 150.5° C.