Abstract: 7.beta.-acylamino-7.alpha.-methoxy-3-pyrazinylthiomethyl-cephalosporins and their intermediates having high resistance toward .beta.-lactamase enzymes, as well as good antibacterial activity and processes for preparation thereof.

Abstract: A new process is disclosed for the preparation of compounds of structure: ##STR1## and are as defined herein characterized in that a compound of structure ##STR2## where R and R.sup.1 have the meanings given herein, is reacted in a suitable solvent with a haloamide in the presence of a metal oxide or a haloamide in the presence of a free radical initiator under the influence of light or heat or alternatively with a halogen in the presence of a metal oxide, to give a compound of structure: ##STR3## where R and R.sup.

Abstract: 7-Acylamino-3-pyrazinylthiomethyl-3-cephem-4-carboxylic acids are disclosed having the general formula: ##STR1## wherein R is an alkyl having from 1 to 5 carbon atoms or ##STR2## wherein Y = Y.sup.1 = HY = y.sup.1 = clY = cl, Y.sup.1 = FY = h,y .sup.1 = cl andIn which n is an integer from 1 to 4, X is O or S, and R.sub.2 is thienyl, phenyl, 1,4-cyclohexadienyl, phenoxy, pyrazinyl and substituted phenyl, thienyl, pyrazinyl and phenoxy, the substituent being selected from the group consisting of hydroxy, chlorine, bromine, and alkyl and alkoxy having from 1 to 4 carbon atoms;R.sub.3 is alkali metal such as sodium or potassium, hydrogen, alkyl having from 1 to 4 carbon atoms, benzyl, trichloroethyl, methoxybenzyl, benzhydryl, pivaloyloxymethyl, and an alkaline earth metal; R.sup.1 may be a pyrazinyl of the general formulae: ##STR3## in which R.sup.4, R.sup.5, R.sup.

Abstract: New 4,5,6,7-tetrahydroimidazo-[4,5-c]-pyridine derivatives are disclosed, and more particularly derivatives of Formula I ##STR1## where R.sub.1 is hydrogen or an alkyl having from 1 to 4 carbon atoms;R.sub.2 is hydrogen, an alkyl having from 1 to 4 carbon atoms, a cycloalkyl having from 3 to 6 carbon atoms, phenyl or a heterocycle;R.sub.3 is hydrogen, a saturated or unsaturated straight or branched alkyl having from 1 to 6 carbon atoms, a cycloalkyl having from 3 to 6 carbon atoms, benzoyl or phenyl; andX is O, S or NR.sub.4 where R.sub.4 is hydrogen, an alkyl having from 1 to 4 carbon atoms, cyano, amino, nitro or acylamino;Or pharmaceutically acceptable acid addition salts thereof.

Abstract: A process is disclosed for the preparation of a compound of the formula ##STR1## where R and R.sup.1 are defined herein below, wherein a compound of the structure; ##STR2## is reacted in a suitable solvent with a haloamide in the presence of a metal oxide or a haloamide in the presence of a free radical initiator under the influence of light or heat or alternatively with a halogen in the presence of a metal oxide, to give a compound of the structure; ##STR3## which compound, in a suitable solvent is reacted with a suitable nucleophilic reagent to obtain the compound; ##STR4## which compound is then subjected to allylic halogenation to give a compound of the structure; ##STR5## which is then reacted with a reducing agent to yield I.