Novel compounds are disclosed having formula (I) as well as pharmaceutically acceptable salts, esters and amides thereof, wherein R1 is selected from (a) loweralkyl, (b) loweralkenyl, (c) halo(loweralkyl), (d) loweralkoxy, (e) cycloalkyl of from 3 to 8 carbons, (f) phenyl, (g) halo, (h) cyano, (i) nitro, (j) bicycloalkyl, (k) loweralkynyl, (l) alkoxycarbonyl, (m) nitrogen-containing aromatic heterocycle and (n) a group of the formula -NR7R8; R2 is selected from the group consisting of halogen, loweralkoxy, carbocyclic aryloxy or carbocyclic aryl(loweralkyl)oxy, loweralkyl, loweralkenyl, cycloalkyl of from 3 to 8 carbons, cycloalkenyl of from 4 to 8 carbons, carbocyclic aryl(loweralkyl), cycloalkyl(loweralkyl), phenyl, amino, (loweralkyl)amino, carbocyclic aryl(loweralkyl)amino, hydroxy-substituted (loweralkyl)amino, nitrogen-containing aromatic heterocycle, bicyclic nitrogen-containing heterocycle and nitrogen-containing heterocycle having formula (II), wherein x is 0 to 3; R9 is selected from (a)-(CH¿2?)m-, wherein m is 1, 2 or 3, and (b) -(CH2)nR?10(CH¿2)p-, wherein R10 is selected from S, O and N, n is 1 or 2, and p is 1 or 2; and Y is a non-hydrogen substituent independently selected from loweralkyl, halo(loweralkyl), loweralkoxy, hydroxy-substituted loweralkyl, hydroxy, amino(loweralkyl), halogen and a group having the formula -NR?11R12; R3¿ is hydrogen, halogen or loweralkoxy; R4 is selected from the group consisting of hydrogen, loweralkyl, a pharmaceutically acceptable cation and a prodrug ester group; R5 is selected from the group consisting of hydrogen, halogen, hydroxy, loweralkyl, halo(loweralkyl), loweralkoxy and a group having the formula -NR13R14; and A is N or CR6, wherein R6 is selected from hydrogen, halogen, loweralkyl, halo(loweralkyl), hydroxy-substituted loweralkyl, loweralkoxy(loweralkyl), loweralkoxy and amino(loweralkyl) or, alternatively, R?1 and R6¿, taken together with the atoms to which they are attached, form a 6-membered saturated ring which may contain an oxygen or a sulfur atom and which may be substituted with loweralkyl; with the proviso that when R5 is hydrogen and A is CH then either (a) R?1 is NR7R8¿, or (b) R2 is a group having formula (III), wherein x is 1-3 and R9 and Y are as defined above.