|   | |
| Names | |
|---|---|
| IUPAC name 1,1',1''-(Ethene-1,1,2-triyl)tribenzene | |
| Identifiers | |
| 3D model (JSmol) | |
| ECHA InfoCard | 100.000.359 | 
|  PubChem CID | |
|  CompTox Dashboard (EPA) | |
| 
 | |
| Properties | |
| C20H16 | |
| Molar mass | 256.348 g·mol−1 | 
| Appearance | white solid | 
| Density | 1.163 g/cm3 [1] | 
| Melting point | 65–67.5 °C (149.0–153.5 °F; 338.1–340.6 K) | 
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Triphenylethylene (TPE) is the organic compound with the formula (C6H5)2C=CH(C6H5). It is a colorless solid.
The compound is prepared in two steps from benzophenone via the intermediacy of 1,2,2-triphenylethanol. [2] Triphenylethylene reacts with iodine to give 9-phenylphenanthroline. [3] Epoxidation gives the chiral oxirane. [4]
Triphenylethylene possesses weak estrogenic activity. [5] [6] Its estrogenic effects were discovered in 1937. [7] TPE was derived from structural modification of the more potent estrogen diethylstilbestrol, which is a member of the stilbestrol group of nonsteroidal estrogens. [8]
TPE is the parent compound of a group of nonsteroidal estrogen receptor ligands. [5] [6] [9] It includes the estrogens chlorotrianisene, desmethylchlorotrianisene, estrobin (DBE), M2613, triphenylbromoethylene, triphenylchloroethylene, triphenyliodoethylene, triphenylmethylethylene; the selective estrogen receptor modulators (SERMs) afimoxifene, brilanestrant, broparestrol, clomifene, clomifenoxide, droloxifene, endoxifen, etacstil, fispemifene, idoxifene, miproxifene, miproxifene phosphate, nafoxidine, ospemifene, panomifene, and toremifene. The antiestrogen ethamoxytriphetol (MER-25) is also closely related, but is technically not a derivative of TPE and is instead a triphenylethanol derivative. The tamoxifen metabolite and aromatase inhibitor norendoxifen is also a TPE derivative. In addition to their estrogenic activity, various TPE derivatives like tamoxifen and clomifene have been found to act as protein kinase C inhibitors. [10]
The affinity of triphenylethylene for the rat estrogen receptor is about 0.002% relative to estradiol. [11] [12] For comparison, the relative binding affinities of derivatives of triphenylethylene were 1.6% for tamoxifen, 175% for afimoxifene (4-hydroxytamoxifen), 15% for droloxifene, 1.4% for toremifene (4-chlorotamoxifen), 0.72% for clomifene, and 0.72% for nafoxidine. [13] [11] [12]