then treating the brominated acid with a strong base and a copper salt to form the desired hydroxy substituted 4 alkoxyphenylacetic acid application_number US 31859089 A description the following example describes the preparation of 3 hydroxy 4 methoxyphenylacetic acid depending upon the hydroxy substitution desired the starting material can be changed to reflect this desired hydroxy substitution additionally the alkoxy substitution can be methoxy ethoxy propoxy isopropoxy butoxy or t butoxy the reaction of 3 hydroxyphenylacetic acid to 3 hydroxy 4 methoxyphenylacetic acid is as follows str2 a mechanically stirred mixture of 4 methoxyphenylacetic acid compound 1 166 2 grams 1 0 mol and 300 ml chloroform was heated to reflux and treated during a period of 4 5 hours with a solution of 55 ml bromine 1 07 mol in 175 ml chloroform the mixture was refluxed for fifteen hours after which time no starting material and only traces of bromine remained the chloroform was distilled under aspirator vacuum until the batch temperature reached 90 u00b0 c two hundred ml of water was added and the mixture was distilled at atmospheric pressure to remove the last of the chloroform until 50 ml of water was collected fifty ml of water was then added and 60 grams 1 5 mol of sodium hydroxide was added to the stirred mixture in small portions maintaining a batch temperature of 80 u00b0 90 u00b0 c with ice bath cooling the mixture was distilled to collect 70 ml of ethanol and water the mixture was then diluted with 70 ml water and transferred to a one liter polypropylene bottle with 200 ml of water treated with 260.