ethyl (RS)-alpha-[(tert-butylsulfonyl)methyl]hydrocinnamate → HCID 54258153, compound

Participants

Reaction Steps

54 g of calcium chloride were added to 97 l of tap water to give a 5 mM solution. The solution was thermostatized to 39°-40° C. while stirring. 6.50 kg of molten ethyl (RS)-α-[(tert-butylsulfonyl)methyl]hydrocinnamate (87% GC) were poured slowly into the warm solution while stirring. The pH value of the emulsion was 7.9. The hydrolysis was started by the addition of 300 g of Optimase M 440 and the pH value was held constant at 7.5 by dosing-in 1N sodium hydroxide solution using automatic titration while stirring. After a consumption of 9.6 l of 1N sodium hydroxide solution (after 22.5 hours), 3 g of DICALITE Speedex and 10 l of ethyl acetate were added to the reaction mixture while stirring and the suspension was filtered. The filtrate was subsequently extracted with 40, 30 and 20 l of ethyl acetate (total amount 90 l). For the rapid phase separation, 2, 0.5 and, respectively, 0.2 kg of sodium sulfate (total amount 2.7 kg) were added each time. The three organic phases were dried over magnesium sulfate and evaporated at 1200 Pa/40° C., whereby 2.39 kg of ethyl (R)-α-[(tert-butylsulfonyl)methyl]hydrocinnamate were obtained. The aqueous phase was adjusted to pH 2.2 with 1.5 l of 25% hydrochloric acid and extracted with 25 and 20 l (total amount 45 l) of ethyl acetate. The first phase separation was accelerated by the addition of 0.2 kg of sodium sulfate. The two organic phases were dried over magnesium sulfate and evaporated at 1200 Pa/40° C., whereby there were obtained 2.22 kg (7.716 mol) of (S)-α-[(tert-butylsulfonyl)methyl]hydrocinnamic acid, which had an enantiomeric excess and a gas-chromatographical purity of, in each case, >99%.

Provenance & Evidence