Synthesis and antibacterial activity of new quinolones containing a 7-[3-(1-amino-1-methylethyl)-1-pyrrolidinyl] moiety. Gram-positive agents with excellent oral activity and low side-effect potential

A series of the R and S isomers of 7-[3-(1-amino-1-methylethyl)-1-pyrrolidinyl]-1,4-dihydro-4-oaoquinoline- and 1,8-naphthyridine-3-carboxylic acids was prepared to determine the effect on potency of the two methyl groups adjacent to the distal nitrogen in the pyrrolidinyl moiety. The antibacterial efficacy of these dimethylated derivatives was compared to the relevant 7-[3(aminomethyl)-1-pyrrolidinyl] parent compounds and, to a lesser extent, the 7-[3-(1-aminoethyl)1-pyrrolidinyl] analogues. The activity of the title and reference compounds was assayed in vitro using an array of Gram-negative and Gram-positive organisms and in vivo using a mouse infection model