In benzothiadiazine diuretics, position 7 is occupied by

Explanation

In the benzothiadiazine/thiazide diuretic structure, a free sulfonamide group at position 7 is important for diuretic activity. Another useful SAR point is that an electron-withdrawing group at position 6—such as chlorine—enhances activity. Hydrochlorothiazide is the classic example.