5-chlorobenzo[b]thiophene-3-carbaldehyde; CAS No.: 16296-68-7; 5-chlorobenzo[b]thiophene-3-carbaldehyde. PROPERTIES: 5-chlorobenzo[b]thiophene-3-carbaldehyde is a crystalline solid. Its molecular formula is C9H6ClOS, and the molecular weight is approximately 207.67 g/mol. The compound has a melting point of approximately 80-82 C. It is moderately soluble in common organic solvents such as dichloromethane and ethyl acetate, but is poorly soluble in water. For proper storage, it should be kept in a sealed container at room temperature, away from heat and direct sunlight. As a compound containing a benzo[b]thiophene ring, a chlorine atom, and an aldehyde group, it may exhibit certain reactivity and stability. When handling it, protective gloves and eye protection should be worn. In case of accidental contact with skin or eyes, immediate rinsing with water is necessary. APPLICATIONS: In organic synthesis, 5-chlorobenzo[b]thiophene-3-carbaldehyde serves as a valuable intermediate. The aldehyde group can undergo various reactions such as nucleophilic addition, oxidation, and condensation. The chlorine atom provides a site for substitution reactions. In the pharmaceutical industry, derivatives of this compound can be explored as potential drug candidates. For example, in the development of certain anticancer drugs, the structure of 5-chlorobenzo[b]thiophene-3-carbaldehyde can be modified to enhance the drug's ability to target cancer cells and improve its therapeutic index (as described in medicinal chemistry research articles). Additionally, in the field of materials science, it can be incorporated into the synthesis of functional materials such as liquid crystals or organic semiconductors, where its structure can influence the material's electronic and optical properties (as mentioned in materials chemistry research papers).