Ammonium bisulfate → (alphaR)-alpha-[(1S)-2-(Dimethylamino)-1-methylethyl]-alpha-ethyl-3-methoxybenzenemethanol

Participants

Reaction Conditions

Reaction Steps

(S)-3-(Dimethylamino)-1-(3-methoxyphenyl)-2-methylpropan-1-one (774.6 g, 3.5 mol, ee 95%) was dissolved in dry tetrahydrofuran (800 mL) in a 10 L double jacket vessel equipped with an electrical impeller stirrer, a gas transition line, Pt100 temperature measuring equipment and an oil based cooling/heating system and ethyl magnesium bromide (2 L, 2 M in THF) was added at a temperature of 15° C. within 2 hours. The reaction mixture was stirred for two hours at that temperature, cooled to 5° C. and aqueous ammonium hydrogen sulfate solution (10% by weight, 2 L) was added. The phases were separated and the organic phase was concentrated in vacuo at 40° C. until a pressure of 5 mbar was reached. (2S,3R)-1-(Dimethylamino)-3-(3-methoxyphenyl)-2-methylpentan-3-ol (871.1 g, 99%) was obtained as a colorless oil (ee 95%).

Provenance & Evidence