Moexipril tert-Butyl Ester Maleic Acid Salt is used in the pharmaceutical industry as a key intermediate in the synthesis of moexipril, an angiotensin-converting enzyme (ACE) inhibitor for treating hypertension. Through hydrolysis, it is converted to moexipril, the active form that inhibits ACE, leading to blood vessel relaxation and reduced blood pressure. The maleic acid salt form enhances the stability and bioavailability of the intermediate during the manufacturing process of oral dosage forms such as tablets.