Amino group

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V. l. right: Primary, secondary and tertiary amines with the functional group marked in blue . R 1 to R 3 is an organyl radical ( alkyl radical, aryl radical, alkylaryl radical, etc.), but not an acyl radical.

In organic chemistry, the amino group is understood to be the functional group (–NH 2 ) of the primary amines and most amino acids . More specifically, amines are divided into three categories: primary, secondary and tertiary amines. They differ in the number of carbons that are bound to the central nitrogen. Primary amines have a carbon bond. Secondary two and tertiary three.

The amino group is a basic functional group because the lone pair of electrons on the nitrogen atom - analogous to that in the ammonia molecule - can accept a proton from an acid HA. This turns it into an ammonium salt .

The formation of ammonium salts through the reaction of amines with a protonic acid HA (HF, HCl, HBr, HI etc.)

Many drugs are ammonium salts ( hydrofluorides , hydrochlorides , hydrobromides , hydroiodides , maleates , acetates, etc.), as these are more stable (longer storable) and often better absorbable than the free amines.

The Kaiser test is proof of amino groups .

Individual evidence

  1. Hans-Dieter Jakubke, Hans Jeschkeit: amino acids, peptides, proteins , Verlag Chemie, Weinheim, 1-505, 1982, ISBN 3-527-25892-2 .
  2. ^ Siegfried Hauptmann : Organic Chemistry , 2nd Edition, VEB Deutscher Verlag für Grundstoffindindustrie, Leipzig, 1985, pp. 487–502, ISBN 3-342-00280-8 .