The preparation of high specific activity [3H]chloramphenicol base and chloramphenicol labeled in the propanediol side chain

✍ Scribed by Elio F. Vanin; Robert H. Symons

• Book ID: 102983851
• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 611 KB
• Volume: 76
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(76)90284-0

✦ Synopsis

Methods are described for the synthesis of [3H]chloramphenicol and derivatives labeled on carbon I of the propanediol side chain. with a specific activity of about 2 mCi/pmol. The labeling step involves the reduction of the 1-0x0 derivative of N-acetyl chloramphenicol base by KB"K to produce a mixture of the D (-) three-and D t -) erythro-diastereoisomers, since carbon I is an asymmetric carbon atom. The two isomers were separated by thin-layer chromatography after acetylation of the two free hydroxyls. After hydrolysis of the three acetyl groups, the biologically active D (-) threw1 I -YH]chloramphenicol base was converted to chloramphenicol. Modification of the above procedures allows the rapid and simple preparation of the mixed D (-J threoand D f -) erythro-isomers of [ I ~ 3Hlchloramphenicol. This mixture can be used where the presence of the inactive D (-) ervthro-isomer of chloramphenicol is not important. The modified procedure also allows the preparation of the mixed isomers of [I-YH]chloramphenicol base and of chloramphenicol analogs. Attempts to prepare a 3-aldehyde derivative of chloramphenicol were not successful. If this could be done, reduction of this derivative with KB"H, would produce the correct isomer of chloramphenicol since carbon atom 3 on the propanediol side chain is not an asymmetric carbon atom.