Dichloromethane → (1S)-1-(3-Ethoxy-4-methoxy-phenyl)-2-methanesulfonyl-ethylamine

Participants

Reaction Conditions

Reaction Steps

After a mixture of (1S)-1-(3-ethoxy-4-methoxyphenyl)-2-methanesulfonyl-ethylamine N-acetyl-L-Leucine salt (1.10 kg, 2.46 moles), deionized water (4.40 L), and dichloromethane (DCM, 5.50 L) was charged into a reaction vessel, a solution of sodium hydroxide (196.0 g, 4.90 moles) in 1.00 L of deionized water was charged into the reaction vessel over about 5 minutes at 15-25° C. The resulting mixture was stirred for at least 10 minutes at 15-25° C. and then the aqueous and organic phases were allowed to separate. The pH of the upper aqueous phase was maintained or adjusted at pH 13-14. The phases were separated and the upper aqueous phase was extracted with DCM (2×4.4 L). The pH of the aqueous phase was maintained at 13-14 throughout the extractions. The DCM extracts were combined and washed with deionized water (3.3 L) until the pH of the aqueous phase reached 11 or less. DCM was removed under vacuum below 35° C. The water content of the residual solid should be <0.1% w/w as measured by Karl Fisher titration. The residual solid was dried azeotropically with more DCM. The solid was dried to a constant weight in vacuo at 30-35° C. to give (1S)-1-(3-ethoxy-4-methoxyphenyl)-2-methanesulfonyl-ethylamine as a white powder (639.0-672.0 g, 95-100% yield).

Provenance & Evidence