Bromine → Sodium

Participants

Reaction Steps

To a solution of 1.53 g of the sodium salt of antibiotic X-537A in 30 ml carbon disulfide was added dropwise a solution of 0.14 ml bromine 10 ml carbon disulfide at -5° over 10 minutes. The solvent was removed under a stream of nitrogen at room temperature (approximately 2 hours). The residue was purified by dissolving it in ethyl acetate and the solution washed successively with aqueous sodium bisulfite and sodium carbonate. After drying (Na2SO4), the solution was evaporated under reduced pressure and the residue crystallized from ethyl acetate to give 5-bromo-3-methyl-6{-7-ethyl-4-hydroxy-3,5-dimethyl-6-oxo-7-[5-ethyl-3-methyl-5-(5-ethyl-5-hydroxy-6-methyl-2-tetrahydro-pyranyl)-2-tetrahydrofuryl]heptyl} salicylic acid, sodium salt as colorless cubes, m.p. 185°, [α]D25 -7.36° (1% in methanol).

Provenance & Evidence