Gabriel synthesis 1729818 221670300 2008-06-25T15:29:58Z Chem-awb 4806773 [[Category:Name reactions]] using [[Project:AutoWikiBrowser|AWB]] 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]]