Metolazone (CAS No. 17560-51-9) is a quinazoline sulfonamide derivative and potent diuretic agent. Chemical formula: C₁₆H₁₆ClN₃O₃S; molecular weight: 365.83 g/mol. Systematic name: 7-Chloro-1,2,3,4-tetrahydro-2-methyl-4-oxo-3-o-tolylquinazoline-6-sulfonamide. This high-purity (≥98%) white solid is used as a reference standard in pharmaceutical research, analytical chemistry, quality control, and drug development.

It is primarily employed clinically as a diuretic to treat fluid retention (edema) associated with congestive heart failure, kidney disorders, and liver disease by increasing urine production to eliminate excess salt and water, reducing swelling and symptoms like shortness of breath. It also manages hypertension by decreasing bloodstream fluid volume. Notably effective in reduced kidney function where other diuretics fail, and often combined with antihypertensives. Electrolyte monitoring is essential in therapeutic use to prevent imbalances like hypokalemia or hyponatremia.

For laboratory/research use only. Not intended for human or veterinary administration.