{{Chembox <!-- Images --> | ImageFile = HCTU Structural Formula V2.svg | ImageSize = | ImageAlt = <!-- Names --> | OtherNames = 2-(6-Chloro-1''H''-benzotriazole-1-yl)-1,1,3,3-tetramethylaminium hexafluorophosphate | IUPACName = ''O''-(1''H''-6-Chlorobenzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate | Section1 = {{Chembox Identifiers | CASNo = 330645-87-9 | ChemSpiderID = 17339147 | EC_number = 608-825-3 | PubChem = 42624899 | StdInChI=1S/C11H15ClN5O.F6P/c1-15(2)11(16(3)4)18-17-10-7-8(12)5-6-9(10)13-14-17;1-7(2,3,4,5)6/h5-7H,1-4H3;/q+1;-1 | StdInChIKey = ZHHGTMQHUWDEJF-UHFFFAOYSA-N | SMILES = CN(C)C(=[N+](C)C)ON1C2=C(C=CC(=C2)Cl)N=N1.F[P-](F)(F)(F)(F)F }} | Section2 = {{Chembox Properties | C=11|H=15|Cl=1|F=6|N=5|O=1|P=1 | Appearance = White to off white powder | Density = | MeltingPt = >185 °C | BoilingPt = | Solubility = }} | Section3 = {{Chembox Hazards | MainHazards = | FlashPt = | AutoignitionPt = | GHSPictograms = {{GHS02}}{{GHS07}} | GHSSignalWord = Warning | HPhrases = {{H-phrases|228|302|315|319|335}} | PPhrases = {{P-phrases|210|240|241|261|264|270|271|280|301+312|302+352|304+340|305+351+338|312|321|330|332+313|337+313|362|370+378|403+233|405|501}} }} }}
'''HCTU''' is an amidinium coupling reagent used in peptide synthesis. It is analogous to HBTU.<ref>{{Cite journal|last1=Marder|first1=Oleg|last2=Shvo|first2=Youval|last3=Albericio|first3=Fernando|date=2003-08-12|title=HCTU and TCTU: New Coupling Reagents — Development and Industrial Aspects|journal=ChemInform|language=en|volume=34|issue=32|doi=10.1002/chin.200332258|issn=1522-2667}}</ref> The HOBt moiety has a chlorine in the 6 position which improves reaction rates and the synthesis of difficult couplings<ref>{{Cite journal|last1=Hood|first1=Christina A.|last2=Fuentes|first2=German|last3=Patel|first3=Hirendra|last4=Page|first4=Karen|last5=Menakuru|first5=Mahendra|last6=Park|first6=Jae H.|date=2008-01-01|title=Fast conventional Fmoc solid-phase peptide synthesis with HCTU|journal=Journal of Peptide Science|language=en|volume=14|issue=1|pages=97–101|doi=10.1002/psc.921|pmid=17890639|issn=1099-1387|citeseerx=10.1.1.595.917|s2cid=24163278}}</ref><ref>{{Cite journal|last1=Sabatino|first1=Giuseppina|last2=Mulinacci|first2=Barbara|last3=Alcaro|first3=Maria C.|last4=Chelli|first4=Mario|last5=Rovero|first5=Paolo|last6=Papini|first6=Anna M.|date=2002-03-01|title=Assessment of new 6-Cl-HOBt based coupling reagents for peptide synthesis. Part 1: Coupling efficiency study|journal=Letters in Peptide Science|language=en|volume=9|issue=2–3|pages=119–123|doi=10.1007/bf02576873|s2cid=29545816|issn=0929-5666}}</ref> HCTU and related reagents containing the 6-chloro-1-hydroxybenzotriazole moiety can be prepared by reaction with TCFH under basic conditions.<ref>{{Cite journal |last1=El-Faham |first1=Ayman |last2=Albericio |first2=Fernando |date=2008-04-01 |title=Morpholine-Based Immonium and Halogenoamidinium Salts as Coupling Reagents in Peptide Synthesis 1 |url=https://pubs.acs.org/doi/10.1021/jo702622c |journal=The Journal of Organic Chemistry |language=en |volume=73 |issue=7 |pages=2731–2737 |doi=10.1021/jo702622c |pmid=18321124 |issn=0022-3263|url-access=subscription }}</ref> It can exist in an N-form (guanidinium) or an O-form (uronium), but the N-form is generally considered to be more stable for this class of reagent.<ref>{{Cite journal |last1=Carpino |first1=Louis A. |last2=Imazumi |first2=Hideko |last3=El-Faham |first3=Ayman |last4=Ferrer |first4=Fernando J. |last5=Zhang |first5=Chongwu |last6=Lee |first6=Yunsub |last7=Foxman |first7=Bruce M. |last8=Henklein |first8=Peter |last9=Hanay |first9=Christiane |last10=Mügge |first10=Clemens |last11=Wenschuh |first11=Holger |last12=Klose |first12=Jana |last13=Beyermann |first13=Michael |last14=Bienert |first14=Michael |date=2002-02-01 |title=The Uronium/Guanidinium Peptide Coupling Reagents: Finally the True Uronium Salts |url=https://onlinelibrary.wiley.com/doi/10.1002/1521-3773(20020201)41:33.0.CO;2-N |journal=Angewandte Chemie International Edition |language=en |volume=41 |issue=3 |pages=441–445 |doi=10.1002/1521-3773(20020201)41:3<441::AID-ANIE441>3.0.CO;2-N|pmid=12491372 |url-access=subscription }}</ref> ''In vivo'' dermal sensitization studies according to OECD 429 confirmed HCTU is a strong skin sensitizer, showing a response at 0.50 wt% in the Local Lymph Node Assay (LLNA) placing it in Globally Harmonized System of Classification and Labelling of Chemicals (GHS) Dermal Sensitization Category 1A.<ref>{{Cite journal |last1=Graham |first1=Jessica C. |last2=Trejo-Martin |first2=Alejandra |last3=Chilton |first3=Martyn L. |last4=Kostal |first4=Jakub |last5=Bercu |first5=Joel |last6=Beutner |first6=Gregory L. |last7=Bruen |first7=Uma S. |last8=Dolan |first8=David G. |last9=Gomez |first9=Stephen |last10=Hillegass |first10=Jedd |last11=Nicolette |first11=John |last12=Schmitz |first12=Matthew |date=2022-06-20 |title=An Evaluation of the Occupational Health Hazards of Peptide Couplers |journal=Chemical Research in Toxicology |language=en |volume=35 |issue=6 |pages=1011–1022 |doi=10.1021/acs.chemrestox.2c00031 |issn=0893-228X |pmc=9214767 |pmid=35532537}}</ref>
== References == {{reflist}}
Category:Peptide coupling reagents Category:Hexafluorophosphates Category:Dimethylamino compounds
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