1,4dihydroquinoline-3-carboxamides

Abstract

Quinolones of the formula I ##STR1## in which the dotted line between positions 2 and 3 of the quinolone ring represents an optional bond; R is hydrogen or lower alkyl; R.sub.1 is lower alkyl; and R.sub.2, R.sub.3 and R.sub.4, which may be the same or different, are hydrogen, halo, lower alkyl, lower alkoxy, lower alkylthio, lower alkylsulphinyl, lower alkylsulphonyl, trifluoromethyl, cyano, fluorinated lower alkoxy, phenyl optionally substituted by one or two substituents selected from lower alkyl, lower alkoxy, lower alkylthio, halo and trifluoromethyl, the group --OAr or the group --S(O).sub.n Ar in which Ar is phenyl optionally substituted by one or two substituents selected from lower alkyl, lower alkoxy, lower alkylthio, halo and trifluoromethyl and n is 0, 1 or 2, or the group --NR.sub.5 R.sub.6 or the N-oxide thereof in which R.sub.5 and R.sub.6, which may be the same or different, are lower alkyl or, together with the nitrogen atom to which they are attached, form a 5-7 membered ring optionally containing an additional hetero atom selected from oxygen, nitrogen and sulphur have utility as antihypertensive agents. Novel quinolones are those of the above-defined formula I, provided that (a) when the optional 2,3-bond is present R.sub.1 is methyl and R is hydrogen, at least one of R.sub.2, R.sub.3 and R.sub.4 is other than hydrogen and (b) when the optional 2,3-bond is present, R is lower alkyl and R.sub.3 and R.sub.4 are hydrogen, R.sub.2 is other than hydrogen or lower alkoxy. Pharmaceutical compositions comprising a novel quinolone of the above formula I together with a pharmaceutically acceptable carrier are described and claimed. Processes for preparing the novel quinolones are also described.