Gabriel synthesis
Overview
 
The Gabriel synthesis is named for the German chemist Siegmund Gabriel
Siegmund Gabriel
-Life and work:Gabriel was born in Berlin and went to school in Berlin. After studying a few semesters at the University of Berlin, Gabriel studied at the University of Heidelberg and received his Ph.D. for work with Robert Wilhelm Bunsen 1874. He was professor at the University of Berlin till...

. Traditionally, it is a chemical reaction
Chemical reaction
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...

 that transforms primary alkyl halides into primary amine
Amine
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...

s using potassium phthalimide
Potassium phthalimide
Potassium phthalimide is a chemical compound of formula C8H4KNO2. It is commercially available, and usually presents as fluffy, very pale yellow crystals. It is the potassium salt of phthalimide...

.

The Gabriel reaction has since been generalized to include the alkylation of sulfonamides and imides, followed by deprotection, to obtain amines (see #Alternative Gabriel reagents).

The utility of the method is based on the fact that the alkylation
Alkylation
Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion or a carbene . Alkylating agents are widely used in chemistry because the alkyl group is probably the most common group encountered in...

 of ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

 is an unselective and inefficient route to amines in the laboratory (on an industrial scale, the alkylation of ammonia is, however, widely employed).
 
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