Ethanoyl Chloride, also known as Acetyl Chloride, is a colorless, corrosive liquid with a pungent odor. It is mainly used in the production of acetic anhydride, which is a major acetylation agent. Its key synonyms include acetic acid chloride, ethanoyl dichloride, and acyl chloride. These terms are commonly used in chemical research and production facilities, and they are all used interchangeably with ethanoyl chloride. Ethyl carboxylate is another synonym for this compound, along with acylation reagent. No matter which term is used, ethanoyl chloride's properties and chemical reactions remain the same. It is important to handle this substance with care and use safety precautions due to its corrosiveness and toxicity.