Acetone → Erythromycin

Participants

Reaction Conditions

Reaction Steps

A mixture of erythromycin thiocyanate and other impurities (100 g) was added into a solvent mixture (300 mL) comprising dichloromethane and acetone (the volume content of dichloromethane is 60%), stirred under heat to 34° C. and adjusted to pH 12 until the solution became clear. The upper aqueous phase was separated and removed to obtain a dichloromethane solution with about 15% of erythromycin A. The dichloromethane solution was cooled to 23° C., kept for one hour and then cooled to 3° C. in 16 hours. The crystals formed were filtered. Dichloromethane (20 mL) (the content of dichloromethane is 95% and ethanol is 5%) was used to wash the crystals and the crystals were filtered for further 5 minutes. The amount of erythromycin A in the dried erythromycin is 94.6% with a dichloromethane content of 352 ppm, a water content of 2.2% and a microbiological titre of 941 μ/mg.

Provenance & Evidence