Erythromycin → Flurithromycin

Participants

Reaction Steps

Erythromycin A (0.5 g, 0.681 mmole) was dissolved in glacial acetic acid (4 mL) at room temperature and stirred for 2 hours. The pH of the mixture was adjusted to 4.3 with 6N sodium hydroxide (approx. 1.2 mL) while the temperature was maintained below 20° C. N-fluoropyridinium pyridine heptafluorodiborate (0.25 g, 0.75 mmole) was added and stirring continued for an additional 2 hours at 22° C. The reaction was worked up in the same manner as Example 1 to afford an 11% yield of crude flurithromycin. Although the yield was only 11%, this example demonstrates operation of the invention with N-F fluorinating agents derived from pyridine since with a co-solvent no flurithromycin is formed. (See Comparative Example 4).

Provenance & Evidence