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Phenacaine

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Phenacaine
Names
IUPAC name
(1E)-N,N-Bis(4-ethoxyphenyl)ethanimidamide
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
UNII
  • 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)
  • O(c1ccc(cc1)N\C(=N\c2ccc(OCC)cc2)C)CC
Properties
C18H22N2O2
Molar mass 298.386 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Phenacaine, also known as holocaine,[1] is a local anesthetic. It is approved for ophthalmic use.[2]

Synthesis

[edit]

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).

Synthesis:[3]

In the patented synthesis,[4] 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

[edit]
  1. ^ "Holocaine Hydrochloride".
  2. ^ Merck Index, 1985
  3. ^ DeWolfe, Robert H. (1962). "Reactions of Aromatic Amines with Aliphatic Ortho Esters. A Convenient Synthesis of Alkyl N-Arylimidic Esters". Journal of Organic Chemistry. 27 (2): 490–493. doi:10.1021/jo01049a036.
  4. ^ DE 79868, Ernst Taeuber, issued 1894