It is known ethacrynic acid, or 4-(2-methylenebutyryl)-2, 3-dichlorophenoxyacetic acid (I), has high diuretic activity [I]. At present, definite interest has been shown in the search for diuretics among compounds with a structure similar to that of I. As the result of investigations among the derivatives of I, very effective diuretics have been found [3-7, 12, 15, 16]. Like I, most of these contain two chlorine atoms and an OCH~ COOH group in their molecule, ...