Originator
Bristalin, Bristol ,US,1952
Manufacturing Process
Sodium methylate is made by dropping 11.7 g of sodium strips into 199 ml of absolute methanol in a 1-liter three-necked flask. 93.9 g of o-benzylphenol are dissolved in 200 ml of dry toluene and added to the sodium methylate solution. The solution is distilled until the boiling point of toluene is reached. At the end of the distillation, enough toluene is added to restore the original volume of solvent.
109.5 g of dimethylaminoethyl chloride hydrochloride and 200 ml of toluene are placed in a 1-liter Erlenmeyer flask, cooled in an ice bath, and decomposed with 167.5 g of 20% sodium hydroxide solution. The toluene and water layers are separated, and the water layer is extracted again with 50 ml of toluene. The toluene layers are combined, washed with saturated salt solution, and dried over anhydrous potassium carbonate.
The dried dimethylaminoethyl chloride solution is poured into the toluene solution of the sodium salt of o-benzylphenol, heated to reflux, and refluxed 16 hours. After refluxing, enough water is added to the mixture to dissolve the precipitated solid. The layers are separated, and the toluene layer is further washed with water until the water extract is just slightly alkaline. The toluene solution is then made acid with 6N hydrochloric acid and extracted with water until no cloudiness is produced when the extract is made alkaline. The acidic aqueous extract is washed with ether, then made alkaline with 20% sodium hydroxide solution, and extracted into ether. The ether solution is washed several times with water, then with saturated salt solution, and is dried over anhydrous potassium carbonate. The dried solution is filtered and distilled. The product distills at 143.5°C/1 mm; 69.7 g of pale yellow oil are recovered.
57.1 g of the free base are dissolved in ether and precipitated with dry HCl. 66.0 g of crude hydrochloride are recovered. The hydrochloride is dissolved in 130 ml of reagent acetone by boiling, filtered hot, and allowed to cool. The crystalline material obtained on cooling is filtered, washed with a little acetone, washed with ether, and dried in vacuo. 44.8 g, MP 119.5°C to 121°C, are recovered from the first crop of crystals. Ethyl acetate may also be used as the solvent for recrystallization.
