Benzamidine
{{Chembox
| Watchedfields = changed
| verifiedrevid = 443415204
| ImageFile = Benzamidine.svg
| ImageSize = 160px
| ImageName = Skeletal formula
| ImageFile1 = Benzamidine-3D-balls.png
| ImageSize1 = 160px
| ImageName1 = Ball-and-stick model
| ImageFile2 = BenzamidineHydrochloride.jpg
| ImageSize2 = 270px
| PIN=Benzenecarboximidamide
| OtherNames=
|Section1={{Chembox Identifiers
| IUPHAR_ligand = 7566
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 2242
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C01784
| InChI = 1/C7H8N2/c8-7(9)6-4-2-1-3-5-6/h1-5H,(H3,8,9)
| InChIKey = PXXJHWLDUBFPOL-UHFFFAOYAU
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 20936
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C7H8N2/c8-7(9)6-4-2-1-3-5-6/h1-5H,(H3,8,9)
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = PXXJHWLDUBFPOL-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo=618-39-3
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = KUE3ZY3J1F
| PubChem=2332
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 41033
| SMILES = [NH]=C(N)c1ccccc1
}}
|Section2={{Chembox Properties
| C=7 | H=8 | N=2
| Appearance= White solid
| Density= 1.22 g/cm3
| MeltingPtC= 64-66
| BoilingPt=
| Solubility=
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|Section3={{Chembox Hazards
| MainHazards=
| FlashPt=
| AutoignitionPt =
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Benzamidine is an organic compound with the formula C6H5C(NH)NH2. It is the simplest aryl amidine. The compound is a white solid that is slightly soluble in water. It is usually handled as the hydrochloride salt, a white, water-soluble solid.{{cite journal|doi=10.15227/orgsyn.081.0105|title=Preparation of 2,4-Disubstituted Imidazoles: 4-(4-Methoxyphenyl)-2-Phenyl-1H-Imidazole|journal=Organic Syntheses|year=2005|volume=81|pages=105|first1= Bryan |last1= Li |first2=Charles K-F |last2=Chiu |first3= Richard F. |last3= Hank |first4= Jerry |last4= Murry |first5= Joshua |last5= Roth |first6= Harry |last6= Tobiassen|doi-access=free}}
Structure
Benzamidine has one short C=NH bond and one longer C-NH2 bond, which are respectively 129 and 135 pm in length, respectively.{{cite journal|doi=10.1107/S0108270196006282|title=Benzamidine|year=1996|last1=Barker|first1=J.|last2=Phillips|first2=P. R.|last3=Wallbridge|first3=M. G. H.|last4=Powell|first4=H. R.|journal=Acta Crystallographica Section C Crystal Structure Communications|volume=52|issue=10|pages=2617–2619}}
The triangular diamine group gives it a distinctive shape which shows up in difference density maps.
Applications
Benzamidine is a reversible competitive inhibitor of trypsin, trypsin-like enzymes, and serine proteases.{{Cite journal|last=Tanizawa|first=Kazutaka|last2=Ishii|first2=Shin-ichi|last3=Hamaguchi|first3=Kazo|last4=Kanaoka|first4=Yuichi|date=1971-05-01|title=Proteolytic Enzymes. VI. Aromatic Amidines as Competitive Inhibitors of Trypsin|url=https://www.jstage.jst.go.jp/article/biochemistry1922/69/5/69_5_893/_pdf/-char/en|journal=The Journal of Biochemistry|volume=69|issue=5|pages=893–899|doi=10.1093/oxfordjournals.jbchem.a129540|pmid=5577153|issn=0021-924X}}
It is often used as a ligand in protein crystallography to prevent proteases from degrading a protein of interest. The benzamidine moiety is also found in some pharmaceuticals, such as dabigatran.
Condensation with various haloketones provides a synthetic route to 2,4-disubstituted imidazoles.
