Content deleted Content added
→Other uses: grammar |
removed Category:Tert-butyl compounds; added Category:Tert-Butyl esters using HotCat |
||
(31 intermediate revisions by 22 users not shown) | |||
Line 1:
{{DISPLAYTITLE:Di-''tert''-butyl dicarbonate}}
{{chembox
| Watchedfields = changed
| verifiedrevid = 477001173
| Name = Di-''tert''-butyl dicarbonate
| ImageFile = Di-tert-butyl-dicarbonate-2D-skeletal.png
| ImageSize =
| ImageName =
| ImageFile1 = Di-tert-butyl-dicarbonate-based-on-similar-xtals-3D-balls.png
|
| OtherNames =
| Section1 = {{Chembox Identifiers
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 48500
Line 16:
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 81704
| EC_number = 246-240-1
| PubChem = 90495
| InChI = 1/C10H18O5/c1-9(2,3)14-7(11)13-8(12)15-10(4,5)6/h1-6H3
Line 25 ⟶ 26:
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 24424-99-5
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = Z10Q236C3G
}}
| Section2 = {{Chembox Properties
| C=10|H=18|O=5
|
▲| Appearance = colourless solid
▲| Solubility = insol
| Solvent = other solvents
| SolubleOther = Soluble in most organic solvents
| MeltingPtC = 22 to 24
| MeltingPt_notes =
Line 39 ⟶ 41:
| BoilingPt_notes = (0.5 mmHg)
}}
|
| ExternalSDS =
| MainHazards = Very toxic on inhalation T+, LC<sub>50</sub> = 100 mg/m<sup>3</sup> (4 hr, rat)}}
| Section8 = {{Chembox Related▼
| OtherCompounds = [[
▲|Section8={{Chembox Related
▲| OtherCompounds = [[ethyl chloroformate]]<br />[[phosgene]]<br />[[diethylpyrocarbonate]]<br />[[dimethyl dicarbonate]]
}}
}}
'''Di-''tert''-butyl dicarbonate''' is a [[reagent]] widely used in [[organic synthesis]].<ref>M. Wakselman, "Di-''t''-butyl Dicarbonate" in ''Encyclopedia of Reagents for Organic Synthesis'' (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. {{
==Preparation==
Di-''tert''-butyl dicarbonate is inexpensive, so it is usually purchased.
[[File:Synthesis of Boc anhydride.png|400px]]
This route is currently employed commercially by manufacturers in China and India. European and Japanese companies use the reaction of [[sodium tert-
Boc anhydride is also available as a 70% solution in [[toluene]] or [[tetrahydrofuran|THF]]. As boc anhydride may melt at ambient temperatures, its storage and handling is sometimes simplified by using a solution.
==Protection and deprotection of amines==
{{main article|
The Boc group can be added to the amine under aqueous conditions using di-''tert''-butyl dicarbonate in the presence of a base such as [[sodium bicarbonate]]. Protection of the amine can also be accomplished in [[acetonitrile]] solution using [[4-dimethylaminopyridine]] (DMAP) as the base.<ref>{{ cite journal |author1=Yochai Basel |author2=Alfred Hassner | title = Di-''tert''-butyl Dicarbonate and 4-(Dimethylamino)pyridine Revisited. Their Reactions with Amines and Alcohols | journal = [[J. Org. Chem.]] | year = 2000 | volume = 65 |issue=20 | pages = 6368–6380 | doi = 10.1021/jo000257f |pmid=11052078 }}</ref>
Removal of the Boc in [[amino acid]]s can be accomplished with strong acids such as [[trifluoroacetic acid]] neat or in [[dichloromethane]]
Selective cleavage of the N-Boc group in the presence of other protecting groups is possible when using AlCl<sub>3</sub>.
Reaction with [[trimethylsilyl iodide]] in acetonitrile followed by methanol is a mild and versatile method of deprotecting Boc-protected amines.<ref>{{ cite journal |author1=Michael E. Jung |author2=Mark A. Lyster | title = Conversion of alkyl carbamates into amines via treatment with trimethylsilyl iodide | journal = [[J. Chem. Soc., Chem. Commun.]] | year = 1978 | pages = 315–316 | doi = 10.1039/C39780000315 | issue = 7 }}</ref><ref>{{ cite journal |author1=Richard S. Lott |author2=Virander S. Chauhan |author3=Charles H. Stammer | title = Trimethylsilyl iodide as a peptide deblocking agent | journal = [[J. Chem. Soc., Chem. Commun.]] | year = 1979 | pages = 495–496 | doi = 10.1039/C39790000495 | issue = 11 }}</ref><ref>{{ cite journal | doi = 10.1016/0040-4020(82)87002-6 | title= Iodotrimethylsilane—a versatile synthetic reagent| year = 1982 | last1 = Olah | first1 = G | last2 = Narang | first2 = S. C. | journal = [[Tetrahedron (journal)|Tetrahedron]] | volume = 38 | issue = 15 | pages = 2225 }}</ref><ref>{{ cite journal |author1=Zhijian Liu |author2=Nobuyoshi Yasuda |author3=Michael Simeone |author4=Robert A. Reamer | title = ''N''-Boc Deprotection and Isolation Method for Water-Soluble Zwitterionic Compounds | journal = [[Journal of Organic Chemistry|J. Org. Chem.]] | year = 2014 | volume = 79 |issue=23 | pages = 11792–11796 | doi = 10.1021/jo502319z | pmid = 25376704 }}</ref>
The use of [[triethylsilane]] as a [[carbocation]] scavenger in the presence of trifluoroacetic acid in [[dichloromethane]] has been shown to lead to increased yields, decreased reaction times, simple work-up and improved selectivity for the deprotection of ''t''-butyl ester and ''t''-butoxycarbonyl sites in protected amino-acids and peptides in the presence of other acid-sensitive protecting groups such as the [[Carboxybenzyl|benzyloxycarbonyl]], [[FMOC|9-fluorenylmethoxycarbonyl]], ''O''- and ''S''-benzyl and ''t''-butylthio groups.<ref>{{cite journal | author = Anita Mehta, R. Jaouhari, T. J. Benson, K. T. Douglas | journal = Tetrahedron Letters | volume = 33 | issue = 37 | date = 1992 | pages = 5441–5444|doi=10.1016/s0040-4039(00)79116-7 }}</ref>▼
▲The use of [[triethylsilane]] as a [[carbocation]] scavenger in the presence of trifluoroacetic acid in [[dichloromethane]] has been shown to lead to increased yields, decreased reaction times, simple work-up and improved selectivity for the deprotection of ''t''-butyl ester and ''t''-butoxycarbonyl sites in protected amino-acids and peptides in the presence of other acid-sensitive protecting groups such as the [[Carboxybenzyl|benzyloxycarbonyl]], [[
==Other uses==
The synthesis of [[6-acetyl-1,2,3,4-tetrahydropyridine]], an important bread aroma compound, starting from [[2-piperidone]] was accomplished using ''t''-boc anhydride.<ref>{{cite journal |
(See [[Maillard reaction]]). The first step in this reaction sequence is the formation of the [[carbamate]] from the reaction of the
:[[Image:BOC application.png|450px|Schematic: synthesis of 6-acetyl-1,2,3,4-tetrahydropyridine]]
Di-''tert''-butyl dicarbonate also finds applications as a polymer [[blowing agent]] due to its decomposition into gaseous products upon heating.<ref>{{cite journal|last1=Wirth|first1=D.|title=Highly Expandable Foam for Lithographic 3D Printing|journal=ACS Appl. Mater. Interfaces|volume=12|issue=16|pages=19033–19043|date=8 April 2020|doi=10.1021/acsami.0c02683|pmid=32267677|s2cid=215603770 }}</ref><ref>{{cite book |last1=Wypych |first1=George |title=Handbook of Foaming and Blowing Agents - 1st Edition |date=20 February 2017 |publisher=ChemTec Publishing |isbn=978-1-895198-99-7 |pages=258 |edition=1st |url=https://www.elsevier.com/books/handbook-of-foaming-and-blowing-agents/wypych/978-1-895198-99-7 |accessdate=4 May 2020}}</ref>
== Hazards ==
Bottles of di-''tert''-butyl dicarbonate buildup of internal pressure in sealed containers caused by its slow decomposition to di-''tert''-butyl carbonate and ultimately ''tert-''butanol and CO<sub>2</sub> in the presence of moisture. For this reason, it is usually sold and stored in plastic bottles rather than glass ones.
The main hazard of the reagent is its inhalational toxicity. Its median lethal concentration of 100 mg/m<sup>3</sup> over 4 hours in rats<ref>{{Cite web|url=https://us.vwr.com/store/asset?assetURI=https://us.vwr.com/stibo/hi_res/eng_us/92/73/12019273.pdf|title=Material Safety Data Sheet|last=|first=|date=|website=|publisher=CHEM-IMPEX INTERNATIONAL INC|access-date=2016-09-10}}</ref> is comparable to that of [[phosgene]]<ref>{{Cite web|url=http://webwiser.nlm.nih.gov/getSubstanceData.do?substanceId=59&displaySubstanceName=Phosgene&STCCID=&UNNAID=&selectedDataMenuItemID=78|title=Phosgene|last=|first=|date=|website=Wireless Information System for Emergency Responders|publisher=US National Library of Medicine|access-date=2016-09-10}}</ref> (49 mg/m<sup>3</sup> over 50 min in rats).
==References==
Line 81 ⟶ 88:
==External links==
* {{cite journal | doi = 10.1055/s-2001-12350 | title = Imidazole and Trifluoroethanol as Efficient and Mild Reagents for Destruction of Excess Di-tert-butyl Dicarbonate [(BOC)2O] | year = 2001 | last1 = Basel | first1 = Yochai | last2 = Hassner | first2 = Alfred | journal = Synthesis | volume = 2001 | issue = 4 | pages = 0550| s2cid = 97029361 }}▼
▲* {{cite journal | doi = 10.1055/s-2001-12350 | title = Imidazole and Trifluoroethanol as Efficient and Mild Reagents for Destruction of Excess Di-tert-butyl Dicarbonate [(BOC)2O] | year = 2001 | last1 = Basel | first1 = Yochai | last2 = Hassner | first2 = Alfred | journal = Synthesis | volume = 2001 | issue = 4 | pages = 0550}}
{{DEFAULTSORT:Di-Tert-Butyl Dicarbonate}}
Line 88 ⟶ 94:
[[Category:Carbonate esters]]
[[Category:Dicarbonates]]
[[Category:Tert-Butyl esters]]
|