We, present inventors, have disclosed in Japanese patent application No. 142558/83 (published as Japanese patent application first publication "Kokai" No. 34957/85 laid open on 22nd Feb. 1985) that an acyl group similar to the .alpha.-(substituted methylene)-.alpha.-aminothizolyl-acetic acid residue or more particularly, the 2-(substituted methylene)-2-(2-aminothiazol-4-yl)-acetic acid residue, presented as the side chain at the 7-position of the new cephalosporin compounds according to this invention is useful as agent for chemical modifications of penicillins and cephalosporins. Also, some .beta.-lactam-compounds which are closely related to the new cephalosporin compounds according to this invention are disclosed in Japanese patent application first publication "Kokai" No. 93982/82, No. 105993/83 and No. 93086/84. The known cephalosporin compounds as disclosed in these three Japanese patent application first publications also have an .alpha.-(substituted methylene)-.alpha.-aminothiazolyl-acetic acid residue as the 7-acyl side chain, similarly to the cephalosporin compounds according to this invention. The new cephalosporin compounds of this invention are different from the above-mentioned known cephalosporin compounds in the respect of the kind of the substituent born on the .alpha.-methylene group of the .alpha.-(substituted methylene)-.alpha.-aminothiazolylacetyl group at the 7-position of the cephalosporin structure.
Cephalosporin-series antibiotics are known to be highly and broadly active against a variety of gram-positive and gram-negative bacteria. Various kinds of semi-synthesized cephalosporin compounds have already been available commercially and applied clinically for the therapeutic treatment of various infections diseases. But, only a very few ones amongst these semi-synthesized cephalosporin compounds are practically effective against the strains of bacteria of the genus Pseudomonas and Proteus. These known cepahlosporin compounds are also degradable by a .beta.-lactamase which is produced by some resistant strains of bacteria, and they exhibit only a poor activity against some resistant strains of bacteria which have now been a target of clinical treatments of bacterial infections (see: W. E. Wick "Cephalosporins and Penicillins, Chemistry and Biology", E. H. Flynn, Academic Press, New York, N.Y., 1972 Chapter 11.)
We, the present inventors, have now succeeded in preparing as the new compound, cephalosporin compounds represented by the general formula (I) as shown below, and we have found that said new cephalosporin compounds exhibit a very wide range of antibacterial spectrum that these compound are highly active not only against a variety of gram-positive and gram-negative bacteria but also against some of resistant strains of bacteria. We have thus reached this invention.