4-chlorobutanoic acid

4-Chlorobutanoic acid (CAS 627-00-9), also known as 4-chlorobutyric acid and gammachlorobutyric acid, is a halogenated organic acid used primarily as a building block in pharmaceutical synthesis. Its reactive chloro and carboxylic acid groups make it a functional intermediate for constructing more complex active pharmaceutical ingredients and specialty molecules. In pharmaceutical manufacturing, it serves as a key intermediate.

This is particularly useful where a four-carbon chain with terminal halogenation is required for cyclization or chain extension reactions. Biotechnology and life sciences researchers use it in the preparation of labeled compounds. It is also utilized for linkers and probe molecules for drug discovery workflows. The compound also supports agrochemical synthesis, where halogenated acid intermediates are used to produce herbicide and pesticide active substances.

Its chloro group enables nucleophilic substitution reactions that are central to constructing gamma-lactam and pyrrolidone ring systems. These systems are found in several drug scaffolds across the medical industry. 4-Chlorobutanoic acid is supplied as a liquid or low-melting solid depending on purity and storage conditions. It is available in technical and high-purity grades suited to pharmaceutical intermediate and research applications.

Packaging ranges from small quantities for laboratory use to bulk quantities for industrial synthesis programs. This ensures that the product meets the specific requirements of both small-scale labs and large manufacturers.