acyl halide
Quick Summary
An acyl halide, also known as an acid halide, is an organic compound characterized by an acyl group (RCO—) bonded to a halogen atom. These compounds are highly reactive and are primarily used in organic synthesis to introduce the acyl group into other molecules.123
Acyl halides are named by replacing the "-ic acid" suffix of the parent carboxylic acid with "-yl halide." For example, the chloride of formic acid is formyl chloride. However, formyl chloride is unstable and decomposes into carbon monoxide and hydrogen chloride. The most common and practical method for synthesizing acyl chlorides involves treating a carboxylic acid with a compound like thionyl chloride.1
Acyl halides are a type of organohalogen compound, which are organic molecules containing at least one halogen atom bonded to carbon. They are distinct from alkyl, vinylic, and aryl halides due to the carbon-halogen bond being doubly bonded to oxygen. Acyl chlorides are the most reactive among acyl halides, followed by anhydrides, esters, and amides, which are progressively less reactive in nucleophilic substitution reactions.21
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