7-Aminocephalosporanic acid → HCID 13022546, compound

Participants

Reaction Conditions

Reaction Steps

40 g of aluminium amalgam are added to a solution of 21.8 g (80 mmols) of 7β-aminocephalosporanic acid in 900 ml of 0.5 M phosphate buffer (pH 7) and 100 ml of dimethylformamide. The mixture is stirred for 1 hour at pH 6.0 and 45° C. After cooling, the reaction mixture is washed with cold ethyl acetate and the aqueous phase is filtered through celite. The filtrate is adjusted to pH 3.5 and evaporated in vacuo and the residue is taken up in 200 ml of methanol-water, 7:3. The portion filtered off (27.5 g) still contains considerable amounts of inorganic salts in addition to the product. 7β-Amino-3-methylene-cepham-4α-carboxylic acid is obtained as an almost colourless powder by shaking with 150 ml of water, leaving the mixture to stand for 3 hours at 0° C, and filtering. Thin layer chromatogram on silica gel: Rf (system 52/n-butanol-glacial acetic acid-water 75:75:21 ) = 0.20, Rf (system 100/ethyl acetate-pyridine-glacial acetic acid-water, 60:20:6:11) = 0.13, Rf (system 200/n-butanol-carbon tetrachloride-methanol-formic acid-water, 30:40:20:5:5) = 0.34.

Provenance & Evidence