Patent ID: 8288514

Claim:
A method of preparing clarithromycin of formula (I) comprising the steps of: providing erythromycin A 9-oxime thiocyanate of formula (II): conducting an etherification reaction by dissolving erythromycin A 9-oxime thiocyanate in an organic solvent to form a solution and adding an etherifying agent into the solution; conducting a silicon alkylation reaction by adding a silanizing agent into product of the etherification reaction to obtain erythromycin A 9-oxime silanization derivatives of formula (III) conducting a methylation reaction by adding a methylating agent into product of the silicon alkylation reaction to obtain methide of formula (IV) conducting a hydrolysis reaction to obtain clarithromycin of formula (I); wherein R 1 is 1-ethoxy-1-methylethyl, 1-methoxyl-1-methylethyl, 2-ethoxypropyl or 1-ethoxycyclohexyl; and R 2 is trimethylchlorosilane.