Benzophenone imine
{{Chembox
| ImageFile = Benzophenone imine.svg
| PIN = Diphenylmethanimine
|Section1={{Chembox Identifiers
| ChemSpiderID = 120561
| PubChem = 136809
| CASNo = 1013-88-3
| EC_number = 600-205-0
| EC_number1 = 440-870-2
| UNII = EJJ21NA7VI
| StdInChI=1S/C13H11N/c14-13(11-7-3-1-4-8-11)12-9-5-2-6-10-12/h1-10,14H
| StdInChIKey = SXZIXHOMFPUIRK-UHFFFAOYSA-N
| SMILES = C1=CC=C(C=C1)C(=N)C2=CC=CC=C2
}}
|Section2={{Chembox Properties
|C=13|H=11|N=1
}}
|Section7 = {{Chembox Hazards
| GHSPictograms = {{GHS07}}
| GHSSignalWord = Warning
| HPhrases = {{H-phrases|315|319|335}}
| PPhrases = {{P-phrases|261|264|271|280|302+352|304+340|305+351+338|312|321|332+313|337+313|362|403+233|405|501}}
}}
}}
Benzophenone imine is an organic compound with the formula of (C6H5)2C=NH. A pale yellow liquid, benzophenone imine is used as a reagent in organic synthesis.
Synthesis
Benzophenone imine can be prepared by the thermal decomposition of benzophenone oxime:{{cite journal |doi=10.15227/orgsyn.010.0028|title=Diphenylmethane Imine Hydrochloride|journal=Organic Syntheses|year=1930|volume=10|page=28|author=Arthur Lachman}}
:2{{nbsp}}(C6H5)2C=NOH → (C6H5)2C=NH + (C6H5)2C=O
Benzophenone imine can also be synthesized by addition of phenylmagnesium bromide to benzonitrile followed by careful hydrolysis (lest the imine be hydrolyzed):{{Cite journal|last1=Pickard|first1=P. L.|last2=Tolbert|first2=T. L.|date=December 1961|title=An Improved Method of Ketimine Synthesis|journal=The Journal of Organic Chemistry|language=EN|volume=26|issue=12|pages=4886–4888|doi=10.1021/jo01070a025|issn=0022-3263}}
:C6H5CN + C6H5MgBr → (C6H5)2C=NMgBr
:(C6H5)2C=NMgBr + H2O → (C6H5)2C=NH + MgBr(OH)
This method is known as Moureu-Mignonac ketimine synthesis.{{Cite book|date=2010-09-15|chapter=Moureau-Mignonac Ketimine Synthesis|journal=Comprehensive Organic Name Reactions and Reagents|language=en|location=Hoboken, NJ, USA|publisher=John Wiley & Sons, Inc.|pages=1988–1990|doi=10.1002/9780470638859.conrr446|isbn=9780470638859}}
Yet another route to benzophenone imine involves reaction of benzophenone and ammonia.{{Cite journal|author1=Verardo, G. |author2=Giumanini, A. G. |author3=Strazzolini, P. |author4=Poiana, M. |title=Ketimines From Ketones and Ammonia|journal=Synthetic Communications|volume=18|issue=13|pages=1501–1511|doi=10.1080/00397918808081307|year=1988}}
Reactions
Benzophenone imine undergoes deprotonation with alkyl lithium reagents.{{cite journal |doi=10.15227/orgsyn.095.0374|title=Trimethylsilyldiazo[13C]methane: A Versatile 13C-Labelling Reagent|year=2018|journal=Organic Syntheses|volume=95|pages=374–402|first1=Chris |last1=Nottingham|first2=Guy C. |last2=Lloyd-Jones|doi-access=free|hdl=20.500.11820/c801073c-6b4b-4a85-be68-2c4313b6e53d|hdl-access=free}}
:(C6H5)2C=NH + CH3Li → (C6H5)2C=NLi + CH4
:(C6H5)2C=NLi + CH3I → (C6H5)2C=NCH3 + LiI
Primary amines can be protected as benzophenone imines, and the protected amines are stable in flash chromatography.{{Cite book|last=O'Donnell|first=Martin J.|date=2001-04-15|chapter=Benzophenone Imine|journal=Encyclopedia of Reagents for Organic Synthesis|language=en|location=Chichester, UK|publisher=John Wiley & Sons, Ltd|doi=10.1002/047084289x.rb031|isbn=978-0471936237}}
Buchwald-Hartwig amination involves coupling aromatic halide and amine to form carbon-nitrogen bonds with the help of palladium-based catalysts. Benzophenone imine can be used as an ammonia-equivalent in such reactions.{{Cite journal|date=1997-09-08|title=An Ammonia Equivalent for the Palladium-Catalyzed Amination of Aryl Halides and Triflates|journal=Tetrahedron Letters|language=en|volume=38|issue=36|pages=6367–6370|doi=10.1016/S0040-4039(97)01465-2|issn=0040-4039|last1=Wolfe|first1=John P.|last2=Åhman|first2=Jens|last3=Sadighi|first3=Joseph P.|last4=Singer|first4=Robert A.|last5=Buchwald|first5=Stephen L.}}