Reaction #65121

Reaction equation

ammonia

erythromycin A

sodium acetate

iodine

→

N-demethylerythromycin A

Yield 40.8%

Solvents

water

methanol water

Conditions

Workup

1. 1
   Otherthe reaction mixture was then irradiated with a quartz lamp at room temperature for 20 minutes
2. 2
   OtherSubsequently, half the solvent was evaporated
3. 3
   Otherthe remaining reaction mixture
4. 4
   ExtractionThe reaction mixture was extracted three times with 20 ml portions of methyl t-butyl ether
5. 5
   ExtractionThe ether extract
6. 6
   Otherwas separated
7. 7
   Othersome of the ether was evaporated
8. 8
   workup.WAITThe reaction product was then left
9. 9
   Otherto crystallize out
10. 10
    Otherwas recrystallized from acetone

Procedure

5 g of erythromycin A and 4.7 g of sodium acetate (×3 H2O) were dissolved in 200 ml of an 8:2 methanol/water mixture. 1.75 g of iodine were added to the solution, and the reaction mixture was then irradiated with a quartz lamp at room temperature for 20 minutes. Subsequently, half the solvent was evaporated, and the remaining reaction mixture was poured into a mixture of 140 ml of water and 10 ml of ammonia. The reaction mixture was extracted three times with 20 ml portions of methyl t-butyl ether. The ether extract was separated and some of the ether was evaporated. The reaction product was then left to crystallize out and was recrystallized from acetone. 2 g of N-demethylerythromycin A were obtained.

Source