Ethanol → Clarithromycin

Participants

Reaction Conditions

Reaction Steps

In the present method, acid is added to the mixture of protected silylated clarithromycin oxime, ethanol, water and deoximating agent and the mixture is heated at reflux (about 80° C.) Heating is then continued and the suspension is stirred for an amount of time sufficient to finish the reaction. The mixture is then cooled to about 20° C. and sodium hydroxide solution having a concentration of from about 20% to about 47%, preferably 47%, is added at this temperature until the pH of the reaction mixture reaches about 10 to about 11, preferably about 10.2 to about 10.5. Crystalline clarithromycin is then isolated, preferably by filtration, with no further water addition. The obtained clarithromycin may subsequently be further purified and/or isolated and the crystalline form of clarithromycin may be altered to the desired form (such as crystal form 0, I, II, or IV) for use.

Provenance & Evidence