of the Joe-ly. 一 anaahgaostataeaaeetctemtry号 In IUPAC nomenclature,nitriles are named from The chain is numbered as in carboxylic acids. 9 9 In the presence of a base, a primary amide undergoes a special halogenation reaction called the Hofmann Rearrangement. When the alkyl group is chiral, its original stereochemistry is retained during the course of the rearrangement. Alkanenitriles: A Special Class of Carboxylic Acid Derivatives 20-8 Nitriles, RC≡N, are considered derivatives of carboxylic acids because the carbon atom is in the same oxidation as the carboxy￾carbon, and nitriles can be converted into other carboxylic acid derivatives. In IUPAC nomenclature, nitriles are named from alkanes. The systematic naming of nitriles is as alkanenitriles. The –ic acid ending of the carboxylic acid is usually replaced with –nitrile. The chain is numbered as in carboxylic acids. Similar rules apply to dinitriles derived from carboxylic acids. As a substituent, -CN is called cyano. Cyanocycloalkanes are called cycloalkanecarbonitriles. The common name, benzonitrile, is generally used rather than the systematic benzenecarbonitrile