Gabriel synthesis
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The '''Gabriel synthesis''', named for the German chemist [[Siegmund Gabriel]], is a [[chemical reaction]] that transforms primary [[alkyl halide]]s into primary [[amine]]s using [[potassium phthalimide]].<ref>{{cite journal
| title = Ueber eine Darstellung primärer Amine aus den entsprechenden Halogenverbindungen
| author = Gabriel, S.
| journal = [[Ber.]]
| date = 1887
| volume = 20
| issue =
| pages = 2224
| url = http://gallica.bnf.fr/ark:/12148/bpt6k90711d/f133.chemindefer}}</ref><ref>{{cite journal
| title = An Improved Procedure for the Condensation of Potassium Phthalimide with Organic Halides
| author = Sheehan, J. C.; Bolhofer, V. A.
| journal = [[J. Am. Chem. Soc.]]
| date = 1950
| volume = 72
| issue =
| pages = 2786
| doi = 10.1021/ja01162a527}}</ref><ref>{{cite journal
| title = The Gabriel Synthesis of Primary Amines
| author = Gibson, M.S.; Bradshaw, R.W.
| journal = [[Angew. Chem. Int. Ed. Engl.]]
| date = 1968
| volume = 7
| issue =
| pages = 919
| doi = 10.1002/anie.196809191}}</ref><ref>Mitsunobu, O. ''Comp. Org. Syn.'' '''1991''', ''6'', 79-85. (Review)</ref>
[[Image:Gabriel Synthesis Scheme.png|500px|center|The Gabriel synthesis]]
The sodium or potassium salt of the product reacts with a primary [[alkyl halide]] to form an alkyl phthalic imide. The reaction fails with secondary alkyl halides.
Upon workup by [[acid|acidic]] [[hydrolysis]] the primary amine is liberated as the amine salt.<ref>{{cite journal
| title = Kinetic Evidence for the Occurrence of a Stepwise Mechanism in the Hydrazinolysis of Phthalimide
| author = Khan, M. N.
| journal = [[J. Org. Chem.]]
| date = 1995
| volume = 60
| issue =
| pages = 4536
| doi = 10.1021/jo00119a035}}</ref> Alternatively the workup may be via the '''Ing-Manske procedure''', involving reaction with aqueous or [[ethanol]]ic [[hydrazine]] at reflux. This produces a precipitate of [[phthalhydrazide]] along with the primary amine. The first technique often produces bad yields or side products; separation of phtalhydrazide can be unpleasant. For these reasons, other methods for liberating the amine from the phthalimide exist.<ref>{{cite journal
| title = An Exceptionally Mild Deprotection of Phthalimides
| author = Osby, J. O.; Martin, M. G.; Ganem, B.
| journal = [[Tetrahedron Lett.]]
| date = 1984
| volume = 25
| issue = 20| pages = 2093
|doi=10.1016/S0040-4039(01)81169-2}}</ref>
==References==
<references/>
[[Category:Substitution reactions]]
[[de:Gabriel-Synthese]]
[[ja:ガブリエル合成]]
[[nl:Gabriel-synthese]]
[[Category:Name reactions]]