Study On The Synthesis Of Roxithromycin

Roxithromycin is derived from erythromycin and is widely used as a safe and effective treatment for a number of bacterial infections. The process of the preparating Roxithromycin consists of: (1) synthesizing erythromycin oxime by erythromycin or erythromycin thiocyanate reacting with hydroxylamino hydrochloride in a good acid-base buffer (2) preparing roxithromycin by erythromycin oxime reacting with (methoxyethoxy)methyl chloride in the presence of a base. Virtually Erythromycin Oxime is the common intermediate of some novel antibiotics such as Clarithromycin, Azithromycin and Dirithromycin.In this thesis, by comparison with two consisted methods a new one to synthesize erythromycin oxime has been designed using erythromycin thiocyanate as raw material. The influence of factors were studied. The optimized conditions were obtained as follows: pH value was around 6.7, reaction temperature was 58-60°C, reaction time was 28 h, the molar ratio of hydroxylammonium chloride and erythromycin thiocyanate was 8.3:1, the time of dissociating hydroxylammonium using 26%(weight) NaOH solution was 30-40 min, and the time of dissociating erythromycin thiocyanate was 30 min.In addition, in the research of the preparation of Roxithromycin, some factors were also discussed. Some optimized conditions were found as follows: the yield of Roxithromycin when (methoxyethoxy)methyl chloride was added more than one time was better than that in the condition of adding (methoxyethoxy)methyl chloride one time, the molar ratio of the quantity of (methoxyethoxy) methyl chloride, the quantity of erythromycin oxime and...