Quinoline compound

A compound of formula I, ##STR10## wherein R.sub.1 and R.sub.2 are each independently of the other hydrogen, lower alkyl, halo-lower alkyl, aryl-lower alkyl, cycloalkyl, halogen, hydroxy, lower alkoxy, halo-lower alkoxy, aryl-lower alkoxy, acyloxy, mercapto, lower alkyl(-thio, -sulfinyl or -sulfonyl), amino, lower alkylamino, di-lower alkylamino, acylamino, nitro, acyl, carboxy, lower alkoxycarbonyl, aminocarbonyl, N-lower alkylaminocarbonyl, N,N-di-lower alkylaminocarbonyl or cyano, or

• R.sub.1 and R.sub.2 together form --(CH.sub.2).sub.m --, wherein m is 3, 4 or 5,
• R.sub.3 is hydrogen, lower alkyl, (carboxy-, lower alkoxycarbonyl-, aminocarbonyl-, N-lower alkylaminocarbonyl-, N,N-di-lower alkylaminocarbonyl- or cyano-)lower alkyl, phenyl-lower alkyl;
• (carboxy-, lower alkoxycarbonyl-, aminocarbonyl-, N-lower alkylaminocarbonyl-, N,N-di-lower alkylaminocarbonyl- or cyano-)phenyl-lower alkyl, which may be additionally substituted in the phenyl ring by lower alkoxy;
• or lower alkyl that is substituted by the group --NHSO.sub.2 R, wherein R is lower alkyl, halo-lower alkyl or aryl,
• R.sub.4 and R.sub.5 are each independently of the other lower alkyl, or
• R.sub.4 and R.sub.5 together form --(CH.sub.2).sub.n --, wherein n is 3, 4, 5 or 6,
• X is O, S, SO or SO.sub.2,
• Ar is 1,3-phenylene or 2,7-naphthylene, and
• Y is hydroxy, lower alkoxy, amino, lower alkylamino or di-lower alkylamino;
• or a salt thereof.