50972-17-3

Penglobe,Astra,W. Germany,1977

ChEBI: A penicillanic acid ester that is the 1-ethoxycarbonyloxyethyl ester of ampicillin. It is a semi-synthetic, microbiologically inactive prodrug of ampicillin.

1'-Ethoxycarbonyloxyethyl 6-(D-α-azidophenylacetamido)penicillinate (98 g) was prepared from sodium 6-(D-α-azidophenylacetamido)penicillinate (397 g, 1 mol), α-chlorodiethylcarbonate (458 g, 3 mols) and sodium bicarbonate (504 g, 6 mols). The product showed strong IR absorption at 2090 cm-1 and 1780-1750 cm-1 showing the presence of azido group and β-lactam and ester carbonyls.
It was dissolved in ethyl acetate (700 ml) and hydrogenated at ambient conditions over a palladium (5%)on carbon catalyst (18 g). The catalyst was removed by filtration and washed with ethyl acetate. The combined filtrates were extracted with water at pH 2.5 by addition of dilute hydrochloric acid. Lyophilization of the aqueous phase gave the hydrochloride of 1'- ethoxycarbonyloxyethyl 6-(D-α-aminophenylacetarnido)penicillinate (94 g), MP 171°-176°C.

Antibacterial

Although comparatively well absorbed (30–55%), the oral efficacy of ampicillin for systemic infections can be enhanced significantly through the preparation of pro-drugs. In contrast to ampicillin itself, which is amphoteric, bacampicillin is a weak base and is very well absorbed in the duodenum (80–98%). Enzymatic ester hydrolysis in the gut wall liberates carbon dioxide and ethanol, followed by spontaneous loss of acetaldehyde and production of ampicillin. The acetaldehyde is metabolized oxidatively by alcohol dehydrogenase to produce acetic acid, which joins the normal metabolic pool.

Store at -20°C