SYNTHESIS AND STRUCTURE-ACTIVITY RELATIONSHIPS IN THE CEFPIROME SERIES III. 7a-METHOXY AND 7a-FORMAMIDO ANALOGUES OF CEFPIROME

7«-Methoxy and 7a-formamido derivatives of cefpirome (HR 810) have been synthesized and tested in comparison with cefpirome and some analogues 1 against aerobic and anaerobic bacteria. Cefpirome and analogues 1 have good activity against Gram-positive and only limited activity against Gram-negative anaerobic bacteria. 7a-Methoxy derivatives 2 show only a slight improvement of activity against Gram-negative anaerobes and are less active against all aerobes. Introduction of the 7a-formamido group (compounds 3) results in an overall loss of activity towards both aerobic and anaerobic bacteria.