Acetone → Erythromycin, anhydro-, N-oxide

220.2 g(0.3 mol) of erythromycin A was dissolved in a mixture of 1,500 ml of methanol and 1,000 ml of water. 79 ml(0.9 mol) of 35% hydrogen peroxide was added dropwise to the solution at a temperature ranging from 15 to 20° C. and stirred at room temperature for 20 hours in a similar method described in E. H. Flynn et al., J. Am. Chem. Soc., 76, 3121(1954) and P. H. Jones et al., J. Org. Chem., 33, 665(1968). The resulting mixture was concentrated to a half volume under a reduced pressure and extracted successively with 1,000 ml and 500 ml portions of chloroform. The combined chloroform extract was washed with brine, dried over anhydrous magnesium sulfate, and then, concentrated under a reduced pressure to obtain a foamy residue. 1,000 ml of acetone was added to the residue and stirred at room temperature for 3 hours. The crystalline material formed was filtered and dried overnight at 45° C. to obtain 220 g of erythromycin a N-oxide in a yield of 98%.

1. customranging from 15 to 20° C.
2. concentrationThe resulting mixture was concentrated to a half volume under a reduced pressure
3. extractionextracted successively with 1,000 ml and 500 ml portions of chloroform
4. extractionThe combined chloroform extract
5. washwas washed with brine
6. dry with materialdried over anhydrous magnesium sulfate
7. concentrationconcentrated under a reduced pressure
8. customto obtain a foamy residue
9. stirringstirred at room temperature for 3 hours
10. customThe crystalline material formed
11. filtrationwas filtered
12. customdried overnight at 45° C.

ORD-Eintrag

ord-536e970e45f44687a879cb070702570c

Quelldatensatz

uspto-grants-2004_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06809188B1