Gist-brocades N.v.

Jan J DeKoning

Hendrik A Witkamp

Jan Verweij

Everardus J Leenderts

Herman H Grootveld

Henri G Hirs

Jan Verwej

A cephalosporin compound substituted in the 7-position with a (cyclo)alkylideneammonio group of formula (II) ##STR1## wherein X' is an anion from an acid HX, R.sub.1 and R.sub.2 are individually a C.sub.1 -C.sub.16 alkyl group, or R.sub.1 and R.sub.2 together with the carbon atom to which they are attached form a cycloalkylidene ring with up to 8 carbon atoms and a process for the preparation which compounds are useful intermediates.

Cephem derivatives

Process for the preparation of 7.beta.-amino-3-substituted methyl-3-cephem-4-carboxylic acid derivatives, new intermediates comprising 7.beta.-(cyclo)alkylideneammonio-3-halomethyl-3-cephem-4-carbox ylic acid derivatives and 7.beta.-amino/ammonio-3-bromomethyl-3-cephem-4-carboxylic acid derivatives and the processes for the preparation of these intermediates.

Cephalosporin derivatives

A process is provided for the preparation of 3-methylene and 3-halomethylene cepham derivatives via 3-phosphoniomethyl-3-cephem derivatives, which in turn can be prepared from 3-halomethyl-3-cephem derivatives. The preparation can be carried out with or without isolating the intermediate phosphonium cephem compounds. The 3-methylene and 3-halomethylene cephem derivatives and in particular the 1-oxo and 1,1-dioxo cephem compounds are also prepared by reducing a 3-halomethyl-3-cephem derivative with activated metal, preferably zinc or magnesium.

Cepham derivatives

Process for the preparation of cephem compounds

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Rijswijk, Netherlands

Jan J DeKoning