Dimethylamine → 1-bromo-3-isopropyl-2-hydroxybenzene

Participants

Reaction Steps

198.1 ml (3.85 mol) of bromine were added dropwise at -5° to 0° to a solution of 470 g of sodium hydroxide in 2 l of water. The mixture was stirred at this temperature for a further 10 min. The resulting sodium hypobromite solution was added dropwise at -5° to 0° C. to a solution of 464 g of a 40% strength aqueous dimethylamine solution (4.11 mol) in 50 ml of water. The mixture was stirred for a further 30 min, then the organic phase was separated off and the aqueous phase was extracted twice using 750 ml portions of methylene chloride. The combined organic phases were briefly dried over magnesium sulfate and filtered. The filtrate was added dropwise at -10° C. to a solution of 500 g (3.67 mol) of ortho-isopropylphenol in 900 ml of methylene chloride. After addition of about 2/3 of the filtrate, a solid formed and the reaction mixture became viscous and difficult to stir. 500 ml of methylene chloride were added at -10° C. and the mixture was stirred for a further hour. The solid was filtered off with suction, washed with a little cold methylene chloride, suspended in 1.5 l of 2N sulfuric acid and stirred at room temperature until all the solid had changed to an oil. The organic phase was separated off and the aqueous phase was extracted with methylene chloride. The combined organic phases were washed with sodium chloride solution and dried, end the solvent was removed in vacuo. The residue was distilled through a 30 cm Vigreux column in a water jet vacuum.

Provenance & Evidence