Amongst the multitude of classes of organic compounds in which substances show diuretic activity, special attention is merited by benzothiadiazine derivatives since one of their representatives (hypothiazide), along with furosemide has a high relative importance in a listing of the international market for current diuretics [2]. A marked diuretic action is also noted tbr derivatives of 2-oxo-4-hydroxyquinoline [3]. The aim of this work is the synthesis of IR-2-oxo-3-(2H-I,2,4- ...