Aminolysis

In chemistry, aminolysis (/am·i·nol·y·sis/) is any chemical reaction in which a molecule is lysed (split into two parts) by reacting with ammonia () or an amine (any molecule containing a nitrogen atom with a lone pair, :N). The case where the reaction involves ammonia may be more specifically referred to as ammonolysis. An example of an aminolysis reaction is the replacement of a halogen in an alkyl group () by an amine () and the elimination of hydrogen halide (HX). R-X + R'-NH2 -> R-NH-R' + HX Another common example is the reaction of a primary amine or secondary amine with a carboxylic acid or with a carboxylic acid derivative to form an amide. This reaction is widely used, especially in the synthesis of peptides. On the simple addition of an amine to a carboxylic acid, a salt of the organic acid and base is obtained. To overcome this, the carboxylic acid first needs to be "activated". This is usually done by converting the acid into a more reactive derivative (i.e. anhydride, acid halide) or by using a coupling agent. In some cases, high temperatures (>200 °C) can overcome salt formation by driving off water, without the need for "activation" of the carboxyl group. The downside to this simple reaction is that the compounds may decompose at these elevated temperatures. The carboxylic acid derivatives can be esters, anhydrides, acid halides or any other activated species. The choice of activated carboxyl group or coupling agent can be very important in peptide synthesis, as using the wrong one can lead to racemization. Making an amide is one of the processes which require ammonia as a reactant. There are other processes of preparing an amide such as from acid anhydrides and acyl chloride. Carboxylic acids react with ammonium carbonate, to convert the carboxylic acids to ammonium salts. For example, acetic acid reacts with ammonium carbonate to produce ammonium acetate.