1-heterocyclyl-1,5-dihydro-pyrido[3,2-b]indol-2-ones of formula (I):
##STR00001## the N-oxides, salts, stereoisomeric forms, racemic
mixtures, prodrugs, esters and metabolites thereof, wherein n is 1, 2 or
3; R.sup.1 is hydrogen, cyano, halo, substituted carbonyl,
methanimidamidyl, N-hydroxy-methanimidamidyl, mono- or
di(C.sub.1-4alkyl)methanimidamidyl, Het.sub.1 or Het.sub.2; X is
NR.sub.2, O, S, SO, SO.sub.2; R.sup.2 is hydrogen, C.sub.1-10alkyl,
C.sub.2-10alkenyl, C.sub.3-7cycloalkyl, which are optionally substituted;
R.sup.2 is aryl substituted with --COOR.sup.4; or R.sup.2 is:
##STR00002## --C.sub.pH.sub.2p--CH(OR.sup.14)--C.sub.qH.sub.2q--R.sup.15
(b-3); --CH.sub.2--CH.sub.2--(O--CH.sub.2--CH.sub.2).sub.m--OR.sup.14
(b-4); --CH.sub.2--CH.sub.2--(O--CH.sub.2--CH.sub.2).sub.m--NR.sup.5aR.su-
p.5b (b-5); -a.sup.1=a.sup.2-a.sup.3=a.sup.4- is --CH.dbd.CH--CH.dbd.CH--;
--N.dbd.CH--CH.dbd.CH--; --CH.dbd.N--CH.dbd.CH--;
--CH.dbd.CH--N.dbd.CH--; --CH.dbd.CH--CH.dbd.N--; wherein hydrogen atoms
in (c-1)-(c-5) may be replaced by certain radicals; R.sup.3 is a
monocyclic or bicyclic aromatic heterocyclic ring system that can be
substituted.
