5-chlorosalicylic acid

5-Chlorosalicylic acid (CAS 321-14-2), also referenced in procurement as 5-CSA, is an organochlorine derivative of salicylic acid used as a building block in pharmaceutical synthesis and as a functional additive in industrial formulations.

Its combination of phenolic and carboxylic acid groups makes it a reactive intermediate for producing active pharmaceutical ingredients and specialty performance chemicals. In pharmaceutical manufacturing, 5-CSA serves as a key intermediate.

It is used in the synthesis of antimicrobial and anti-inflammatory APIs, where controlled chlorination and hydroxyl positioning are critical to the final molecule's activity. Coating and resin formulators incorporate it as a UV stabilizer.

It also acts as an antioxidant to extend the service life of protective coatings exposed to outdoor weathering. In adhesive and sealant systems, it contributes biocidal and preservation properties that inhibit microbial degradation.

These properties help maintain the product's shelf life. Personal care formulators also evaluate it as a preservative-boosting component in leave-on and rinse-off products where broad-spectrum efficacy is required.

5-Chlorosalicylic acid is supplied as a white to off-white crystalline powder. Technical and pharmaceutical-grade material is available, with pharmaceutical-grade product typically meeting defined purity thresholds.

This grade is suitable for API intermediate use. Packaging ranges from kilogram-scale laboratory quantities to bulk drum supply for industrial procurement, ensuring flexibility for various manufacturing scales and requirements.