76801-85-9

342371-84-0

76801-85-9

Example-2; [93] [94] Preparation of 9-deoxy-9a-azo-9a-homoerythromycin A; Acetic acid was added dropwise to a methanolic (700 mL) suspension of 6,9-imino ether (II) (70.0 g), and the pH was adjusted to 5-6. Subsequently, an aqueous solution of PtO2 (7.0 g) was added to the above mixture and the reaction was carried out under a hydrogen pressure of 8-9 kg/cm2 and a temperature of 40-45°C for 4-5 hours for the hydrogenation reduction reaction. After completion of the reaction, the reaction mixture was filtered through Hyflo Super Cel and the filter cake was washed with methanol. The filtrates were combined and the methanol was removed by distillation under reduced pressure. To the residue, deionized water (700 mL) was added and the pH was adjusted to 11-12 with aqueous sodium hydroxide.The precipitated solid was filtered, drained, and dried in an oven to afford 9-deoxy-9a-azo-9a- homoerythromycin A(III) (55.0 g) in 85% yield.