View source for Chemistry:2-tert-Butyl-1,1,3,3-tetramethylguanidine

{{DISPLAYTITLE:2-''tert''-Butyl-1,1,3,3-tetramethylguanidine}}
{{Chembox
| Name = 2-''tert''-Butyl-1,1,3,3-tetramethylguanidine
| ImageFile = 2-tert-butyl-1,1,3,3-tetramethylguanidine.png
| ImageSize = 170
| ImageAlt = 2-''tert''-butyl-1,1,3,3-tetramethylguanidine
| PIN = ''N''{{prime}}{{prime}}-''tert''-Butyl-''N'',''N'',''N''{{prime}},''N''{{prime}}-tetramethylguanidine
| OtherNames = BTMG, Barton's base
| Section1 = {{Chembox Identifiers
| CASNo = 29166-72-1
| PubChem = 3571581
| ChemSpiderID = 2808676
| StdInChI=1S/C9H21N3/c1-9(2,3)10-8(11(4)5)12(6)7/h1-7H3
| StdInChIKey = YQHJFPFNGVDEDT-UHFFFAOYSA-N
| SMILES = CC(C)(C)N=C(N(C)C)N(C)C
  }}
| Section2 = {{Chembox Properties
| C=9|H=21|N=3
| Appearance = 
| Density = 
| MeltingPt = 
| BoilingPt = 
| Solubility = 
  }}
| Section3 = {{Chembox Hazards
| MainHazards = 
| FlashPt = 
| AutoignitionPt = 
| GHSPictograms = {{GHS05}}{{GHS07}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|302|314}}
| PPhrases = {{P-phrases|260|264|270|280|301+312|301+330+331|303+361+353|304+340|305+351+338|310|321|330|363|405|501}}
  }}
}}

'''2-''tert''-Butyl-1,1,3,3-tetramethylguanidine''' is an [[Chemistry:Organic base|organic base]], also known as '''Barton's base'''. It is named after Nobel Prize-winning British chemist [[Biography:Derek Barton|Derek Barton]]. Barton and his assistants prepared a series of [[Chemistry:Guanidine|guanidine]]s with [[Chemistry:Steric effects|steric hindrance]] in 1982; in this case five [[Chemistry:Alkyl|alkyl groups]]: four [[Chemistry:Methyl group|methyl group]]s and one ''tert''-butyl group.<ref name=":0">{{cite journal |last1=Barton |first1=Derek H. R. |last2=Elliott |first2=John D. |last3=Géro |first3=Stephen D. |title=Synthesis and properties of a series of sterically hindered guanidine bases |journal=J. Chem. Soc., Perkin Trans. 1 |date=1982 |pages=2085–2090 |doi=10.1039/P19820002085}}</ref><ref>{{cite book |title=Reason and imagination : reflections on research in organic chemistry : selected papers of Derek H.R. Barton |year=1996 |publisher=World Scientific/Imperial College Press |isbn=9810213611}}</ref> In 50% water ethanol mixture, the acidity constant (p''K''<sub>a</sub>) of Barton's base is 14.<ref name=":0" /> In acetonitrile its p''K''<sub>a</sub> is 24.31.

== Synthesis ==
The base is prepared by the reaction of ''tert''-butylamine with a [[Chemistry:Vilsmeier reagent|Vilsmeier salt]]. The latter is the reaction product of [[Chemistry:Phosgene|phosgene]] with [[Chemistry:Tetramethylurea|tetramethylurea]].

== Applications ==
Barton's base can be used in many organic reactions, including in alkylations and in the formation of [[Chemistry:Aziridine|aziridine]]s. It is often a milder alternative to traditional, strong inorganic bases.

==References==
<references />

{{DEFAULTSORT:Butyl-1, 1, 3, 3-tetramethylguanidine, 2-tert-}}
[[Category:Guanidines]]
[[Category:Non-nucleophilic bases]]

{{Sourceattribution|2-tert-Butyl-1,1,3,3-tetramethylguanidine}}