反応 #52549

反応方程式

NaOH

formic acid

9-Deoxo-9a-aza-9a-homoerythromycin A

formaldehyde

→

Azithromycin monohydrate

溶媒

acetonitrile

反応条件

後処理

1. 1
   workup.ADDITIONwere added
2. 2
   温度refluxed for 24 hours
3. 3
   ろ過filtered
4. 4
   その他to remove particles
5. 5
   workup.ADDITIONTo the filtered acetonitrile solution, an equal volume of water was added
6. 6
   その他to precipitate Azithromycin monohydrate as cube
7. 7
   ろ過The crystals were filtered
8. 8
   その他dried under vacuum at 50° C.

実験手順

9-Deoxo-9a-aza-9a-homoerythromycin A (73.5 g —0.1 mole) was dissolved in 250 ml acetonitrile. To this solution, formic acid (19 ml, 0.5 mole) followed by formaldehyde (37%, 20 ml, 0.25 mole) were added and refluxed for 24 hours. The pH of the reaction mixture was adjusted with alkali (NaOH solution) to 10.5 and filtered to remove particles. To the filtered acetonitrile solution, an equal volume of water was added to precipitate Azithromycin monohydrate as cube shaped crystals. The crystals were filtered and dried under vacuum at 50° C. to give 65 g of Azithromycin monohydrate having water content of 5% (water content measured by the Karl Fischer titration method). This sample of Azithromycin monohydrate crystals has a characteristic solid state (KBr pellet) IR spectrum (FIG. 1) and a characteristic X-ray diffraction pattern (FIG. 2).

出典