Patent ID: 7071314

Claim:
A method of preparing a 2′, 4″-hydroxyl protected 6-O-alkenylarylerythromycin A derivative comprising the steps of: protecting the 2′-hydroxyl and 4″-hydroxyl groups of a 6-hydroxyl, 2′-hydroxyl, 4″-hydroxyl erythromycin A derivative with at least one hydroxyl-protecting agent to form a 6-hydroxyl, 2′, 4″-hydroxyl protected erythromycin A derivative; allylating the C-6 hydroxyl of said 6-hydroxyl, 2′, 4″-hydroxyl protected erythromycin A derivative with an allylating agent to form a 6-O-allyl, 2′, 4″-hydroxyl protected erythromycin A derivative; arylating said 6-O-allyl, 2′, 4″-hydroxyl protected erythromycin A derivative with an arylating agent in the presence of an inorganic base, a phase transfer catalyst and less than six mole percent of a palladium catalyst in an organic solvent, without addition of a phosphine, at a temperature of from about 90° C. to about 120° C., for about 3 hours, to form a 2′, 4″-hydroxyl protected 6-O-alkenylarylerythromycin A derivative; and then, optionally isolating said 2′, 4″-hydroxyl protected 6-O-alkenylaryl erythromycin A derivative.