Nitrile hydratases are metalloenzymes that hydrolyze nitriles to amides. These derivatives include salts, chlorides, esters, amides, and anhydrides. These include aliphatic and cycloaliphatic amines, polyaminoamides, amides, and anhydrides. These reagents require ethers, not nitriles, amides, sulfoxides, etc. Aniline reacts with acyl chlorides such as acetyl chloride to give amides. Specifically they are often used to convert carboxylic acids to amides or esters. With good nucleophiles such as thiols, amines, and even amides, no acid catalyst is required. DCC is a dehydrating agent for the preparation of amides, ketones, nitriles. Common nucleophiles besides acetates are arenes, alkenes, amides, and phenols. Instead esters are typical precursors to amides. Detergents are obtained from amides and quaternary alkylammonium derivatives of stearic acid. The solubilities of amides and esters are roughly comparable. CDI is mainly employed to convert amines into amides, carbamates, ureas. They are the imine derivatives of amides (RC(O)NR). Low molecular weight amides, such as dimethylformamide, are common solvents.