Hydrochloric Acid → 2-Hydroxy-3,4,6-trimethylbenzoic acid phenylester

Participants

Reaction Conditions

Reaction Steps

In a 500 ml three-necked flask fitted with a mechanical stirrer, a reflux condenser connected to a water pump to absorb the gaseous hydrochloric acid formed during the reaction, and a dropping funnel, were placed 200 ml of dry toluene and 54 g (0.3 mole) of 2-hydroxy-3,4,6-trimethylbenzoic acid prepared in step (1), and 56.4 g (0.6 mole) of phenol were added. The mixture was heated at 100° C. until the reagents were completely dissolved. 27 ml of phosphorus oxychloride were then added dropwise over 30 minutes, and the mixture was refluxed (110° C.) for 8 hours. A substantial evolution of gaseous hydrochloric acid took place. The mixture was cooled to 80° C. and 150 ml of water were added. The aqueous layer was decanted, and the organic layer was washed a second time with an aqueous solution of sodium bicarbonate. The aqueous layer was decanted and the toluene solution was dried with anhydrous magnesium sulfate. The solution was filtered, and the toluene solvent was distilled off. The residue was dissolved in 90 ml of boiling isopropanol and the desired product crystallized upon cooling. 38 g of a white product were obtained (M.P.=74° C.).

Provenance & Evidence