Erythromycin Estolate

Add 20g water and 50g erythromycin thiocyanate to 140g acetone, heat to 35-38℃, stir for 5 minutes, add 9g triethylamine to desulfurize erythromycin thiocyanate to free erythromycin base, and the system is clear;

Add 13.5g propionic anhydride at 35-38℃, react for 120 minutes to generate erythromycin propionate; filter;

Add dodecyl sulfate solution (dodecyl sulfate solution) then.

The dodecyl sulfate solution was prepared as follows: dodecyl sulfate:water = 17g:90g. The reaction was maintained at this temperature for 60 minutes to generate erythromycin. 50g of water was added at 35-38℃ to make the solution turbid, and the mixture was stirred for 60 minutes to precipitate a large amount of erythromycin. 500g of water was added, and the temperature was lowered to 5-10℃ for crystallization. After centrifugation, the filter cake was washed with water and dried to obtain 61g of erythromycin. The yield was 61/50 = 122%. The product produced using the above process is a white crystalline powder; almost odorless, with a melting point of 132-138℃, readily soluble in ethanol or chloroform, and almost insoluble in water. Elemental analysis showed that the elemental values were close to the theoretical values.