Aküülkloriide

Aküülkloriide is the Estonian term for acyl chlorides. Acyl chlorides are a class of organic compounds with the general formula RCOCl, where R is an alkyl or aryl group and Cl is a chlorine atom. They are derived from carboxylic acids by replacing the hydroxyl group (-OH) with a chlorine atom (-Cl). This structural feature makes them highly reactive electrophiles.

Acyl chlorides are important intermediates in organic synthesis due to their reactivity. They readily undergo nucleophilic acyl substitution reactions with a variety of nucleophiles, including water, alcohols, amines, and carboxylates. For example, reaction with water produces the corresponding carboxylic acid and hydrochloric acid. With alcohols, they form esters and hydrochloric acid. With amines, they yield amides and hydrochloric acid. These reactions are often facile and can be carried out under relatively mild conditions.

The preparation of acyl chlorides typically involves reacting a carboxylic acid with a chlorinating agent. Common reagents include thionyl chloride (SOCl2), phosphorus trichloride (PCl3), or phosphorus pentachloride (PCl5). For example, the reaction of acetic acid with thionyl chloride yields acetyl chloride, a common acyl chloride.

Due to their reactivity, acyl chlorides are often irritating and corrosive and should be handled with care in a well-ventilated area. They are sensitive to moisture and can hydrolyze rapidly in the presence of water. Their applications are primarily in the synthesis of other organic compounds, such as esters, amides, and acid anhydrides, which have widespread uses in pharmaceuticals, polymers, and fragrances.