5-Chloro-2-acetylthiophene is a halogenated heterocyclic ketone widely employed as a pharmaceutical intermediate, particularly in cephalosporin antibiotics synthesis. The compound exhibits a density of 1.312 g/cm³ at 25°C, boiling point of 117-118°C (20 mmHg), and flash point of 227°F. Its refractive index is 1.559 (20°C). Storage should be in tightly sealed containers under inert gas at 2-8°C to prevent decomposition. Safety measures require acid-resistant gloves/face shields due to its irritant properties (GHS Category 2). The acetyl and chloro substituents on the thiophene ring make it a versatile building block for Suzuki couplings and other cross-coupling reactions in medicinal chemistry.
