2(1H)-Chinolinon-Verbindungen, Verfahren zu deren Herstellung und diese enthaltende pharmazeutische Zusammensetzungen

1. A compound of the formula : wherein R is imidazopyridyl, thiazolyl, indolyl, dihydroindolyl, imidazolyl, benzimidazolyl, quinolyl, isoquinolyl, quinazolinyl, dihydroisoquinolyl, tetrahydroimidazopyridyl or tetrahydroquinolyl, each of which may be substituted with substituent(s) selected from the group consisting of lower alkyl, halogen, lower alkoxy, lower alkylthio, ar(lower)alkoxy, cyano, nitro, amino, lower alkylamino, acylamino, hydroxy and oxo, R is hydrogen, lower alkyl or halogen, A is a single bond or a group of the formula selected from the group consisting of : -CO-X @, -@@-X- and -X-CO-, in which X is a single bond or lower alkylene and X is lower alkylene, and a heavy solid line means a single or a double bond, and its pharmaceutically acceptable salt, processes for their preparation and pharmaceutical compositions comprising them as an active ingredient, in association with a pharmaceutically acceptable, substantially non-toxic carrier or excipient.