Erythromycin Impurity E(EP) synthesis

Yield:857839-61-3 71%

Reaction Conditions:

with acetic acid at 20; for 2 h;

Steps:

1

Starting Material Synthesis Example 1 Synthesis of 8,9-anhydroerythromycin A 6,9-hemiketal (EM201) A solution (710.0 mL) of EMA (erythromycin A; 104.4 g, 16.90 mmol) in glacial acetic acid was stirred at room temperature for 2 hr, and aqueous NaHCO₃ solution was slowly added to neutralize the solution. The reaction mixture was extracted with CHCl₃, and the organic layer was dried over Na₂SO₄. The residue was filtrated, and the filtrate was concentrated to give a crude product (99.30 g). The obtained crude product was dissolved in CHCl₃ (250 mL), and the solution was recrystallized by adding hexane (50 mL) to give EM201 (74.50 g, 71%) as a white powder.

References:

EP1950219,2008,A1 Location in patent:Page/Page column 15