reaction mixture some product has separated is added to 1 2 liters of cold water the material is extracted with 3 1 ether dichloromethane five 300 ml portions the combined extracts are dried over magnesium sulfate and the solvents are removed on a rotary evaporator to give a semi solid residue crystallization of the residue from 300 ml of diisopropyl ether yields 86 g of product melting point 86 u00b0 88 u00b0 c a stirred solution of 15 g of 2 4 3 dimethylamino propoxy phenyl methylene 3 4 dihydro 1 2h naphthalenone in 150 ml of tetrahydrofuran is treated with 25 ml of 3 m methyl magnesium bromide the temperature rises to 50 u00b0 c after 4 hours at room temperature the mixture is poured into a cold solution of 7 0 g of ammonium chloride in 70 ml of water and the product is extracted with ether three 150 ml portions the combined extracts are dried over magnesium sulfate and the solvent removed on a rotary evaporator to give 16 7 g of the free base of the title compound as an oil the base 13 2 g is dissolved in 65 ml of acetonitrile and treated with a warm solution of 3 4 g of oxalic acid in 50 ml of acetonitrile on seeding the crystalline oxalate salt rapidly separates after cooling overnight the product weighs 12 9 g and has a melting point of 100 u00b0 103.