:Phenacaine
{{chembox
| ImageFile = Phenacaine.svg
| ImageSize = 200px
| IUPACName = (1E)-N,{{prime|N}}-Bis(4-ethoxyphenyl)ethanimidamide
| OtherNames =
|Section1={{Chembox Identifiers
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = V3M4D317W8
| CASNo = 101-93-9
| PubChem = 7588
| ChEMBL = 127123
| ChemSpiderID = 7307
| SMILES = O(c1ccc(cc1)N\C(=N\c2ccc(OCC)cc2)C)CC
| InChI = InChI=1S/C18H22N2O2/c1-4-21-17-10-6-15(7-11-17)19-14(3)20-16-8-12-18(13-9-16)22-5-2/h6-13H,4-5H2,1-3H3,(H,19,20)
}}
|Section2={{Chembox Properties
| C=18 | H=22 | N=2 | O=2
| Appearance =
| Density =
| MeltingPt =
| BoilingPt =
| Solubility =
}}
|Section3={{Chembox Hazards
| MainHazards =
| FlashPt =
| AutoignitionPt =
}}
}}
Phenacaine, also known as holocaine,{{cite web | url = http://www.chemicalbook.com/ChemicalProductProperty_EN_CB8407869.htm | title = Holocaine Hydrochloride}} is a local anesthetic. It is approved for ophthalmic use.Merck Index, 1985
Synthesis
The synthesis of phenacaine begins with the condensation of p-phenetidine (1) with triethyl orthoacetate (2) to afford the imino ether (a Pinner salt, 3). Reaction of that intermediate with a second equivalent of the aniline results (4) in a net displacement of ethanol, probably by an addition-elimination scheme, producing the amidine, phenacaine (5).
In the patented synthesis,{{Cite patent | country = DE | number = 79868 | gdate = 1894 | inventor = Ernst Taeuber }} phenacetin was used as precursor. Treatment with phosphorus trichloride (PCl3) gave the enol chloride, and reaction of this intermediate with p-phenetidine then completed the synthesis of phenacaine.
References
{{Local anesthetics}}
{{nervous-system-drug-stub}}