| 摘要 |
1324419 N-haloalkanoyl derivatives of cephalosporin C ELI LILLY & CO 12 Oct 1970 [17 Dec 1969] 48320/70 Heading C2A Cephalosporin C is converted to an N-haloalkanoyl derivative of formula wherein R is an α-halo or α,α-dihalo-C 2 -C 4 alkanoyl group, by acylating the amino group in the adipoyl side chain with a corresponding haloalkanoyl halide or anhydride. The cephalosporin C may be treated in aqueous solution, e.g. a productive fermentation broth which preferably has been filtered and if necessary concentrated, to convert it to the said derivative which is easily extracted from the aqueous medium with a water-immiscible solvent such as ethyl acetate. The acylating agent is preferably an α-halo or α,α-dihaloalkanoyl chloride or mixed anhydride (e.g. acetic chloroacetic anhydride). The solvent extraction is best conducted at acid pH and immiscible solvents used include propyl or butyl acetate, nitriles and ketones. Alkyl esters may be mixed with one tenth to one volume of C 2 to C 4 alkanol. The derivative may subsequently be isolated by, e.g. adding an alkali to the solution to precipitate it as a salt. The formation of the derivative provides a convenient means for separating cephalosporin C from its productive fermentation broth. |
