SUBSTITUTED QUINOLINE DERIVATIVE,ITS PRODUCTION,AND ITS USE

4-Methylene-2-quinolones of formula (I) and their tautomers of formula (Ia) and their isomers, salts and prodrugs are new: n = 0-4; R1 = halo, CF3, OCF3, OH, alkyl, cycloalkyl, alkoxy, alkoxyalkoxy, alkylthio, alkylsulphinyl, alkylsulphonyl, NO2, NH2, azido, alkylamino, dialkylamino, piperidino, morpholino, pyrrolidino, acyl, acyloxy, acylamino, CONH2, COOH, alkoxycarbonyl, SO3H, SO2NH2, Ar, OAr, COOAr, SAr, SOAr, SO2Ar, SO3Ar, OSO2Ar, SO2NHAr, NHSO2Ar, COAr, Ar', etc.; Ar,Ar' = phenyl and heteroaryl resp., etc.; X = O, S, Se, NR2 or NOR2; R2 = H; alkyl opt. substd. by halogen, CN, NH2, OH, etc.;R5, R6 = COOH or gps. as defined for R2; or R5+R6 forms a 3-8C carbocyclic ring; R3,R4 = alkyl, alkenyl, cycloalkyl or cycloalkenyl,etc.; or R3+R4 = a 3-8C carbocyclic ring; or R3+R4 = CZ1Z2 gp., where Z1 and Z2 are as defined for R3 and R4 as above; provided that X is not O when R1=R2=R5=R6=H and R3=R4=Me or R3+R4= (CH2)4.