Acetone → 9-Deoxo-9a-aza-9a-homoerythromycin A

Beteiligte Stoffe

Reaktionsschritte

In accordance with one aspect of the present invention, there is provided a method of preparing azithromycin of formula (I) comprising the steps of: (a) reducing 6,9-imino ether of formula (III) dissolved in methanol with 5 to 7 mole equivalents of NaBH4 at −20 to −10° C., treating the reaction mixture with an acidic aqueous acetone solution of citric acid, and adjusting the solution pH to 10.5 to 12.0 to obtain a crystalline hydrate of 9-deoxo-9a-aza-9a-homoerythromycin A of formula (II); and

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