تفاعل #52549

معادلة التفاعل

NaOH

formic acid

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

formaldehyde

→

Azithromycin monohydrate

المذيبات

acetonitrile

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONwere added
2. 2
   درجة الحرارةrefluxed for 24 hours
3. 3
   ترشيحfiltered
4. 4
   أخرىto remove particles
5. 5
   workup.ADDITIONTo the filtered acetonitrile solution, an equal volume of water was added
6. 6
   أخرىto precipitate Azithromycin monohydrate as cube
7. 7
   ترشيحThe crystals were filtered
8. 8
   أخرىdried under vacuum at 50° C.

الإجراء التجريبي

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).

المصدر