Potassium Carbonate → LY 267108

Participants

Reaction Steps

Glacial acetic acid solution of erythromycin (12.4 g) was stirred at room temperature for 2 hours, added slowly aqueous sodium hydrogen carbonate and neutralized. The reaction mixture was extracted with chloroform, dehydrated the organic layer with mirabilite, filtered off the mirabilite and removed the solvent by distillation to obtain crude substance. The crude substance was purified with silica gel column chromatography (chloroform:methanol:aqueous ammonia=10:0.5:0.01→10:1:0.05) to obtain EM201 (7.7 g). Subsequently, potassium carbonate (1.4 g) was added to the methanol solution of EM201 (7.6 g) and refluxed for 2 hours. After distilled off the solvent, the residue was dissolved in aqueous sodium hydrogen carbonate and extracted with chloroform. The mixture was dehydrated with mirabilite, filtered and removed the mirabilite, then the obtained crude substance was purified by silicagel column chromatography (chloroform:methanol:aqueous ammonia=10:0.5:0.01→10:1:0.05) to obtain EM701 (5.9 g, white powder).

Provenance & Evidence