Triphenylbromoethylene

Triphenylbromoethylene, also known as bromotriphenylethylene or as phenylstilbene bromide, is a synthetic nonsteroidal estrogen of the triphenylethylene group that was marketed in the 1940s similarly to the closely related estrogen triphenylchloroethylene.

SAR

A diethoxylated derivative of triphenylbromoethylene, estrobin, is also an estrogen, but, in contrast, was never marketed. An ethylated derivative of triphenylbromoethylene, broparestrol, is a selective estrogen receptor modulator that has been marketed.
Although the vinylic halogens has already been discussed, it was discovered that Triphenylacrylonitrile also potently modulates the estrogen receptor.

The synthesis of triphenylbromoethylene has been discussed previously:
Grignard reaction of Triphenylbromoethylene with carbon dioxide gives a compound that is called Triphenylacrylic acid . The acid can then undergo esterification with Diethylethanolamine . This agent was claimed to have hormonal activity but was also stated to function as a coronary vasodilator. In terms of the SAR it is counselled to consider an agent that is called Cinnamaverine . Cinnamaverine has the same structure as the compound just described but differs in that it was made by the esterification of 2,3-diphenylacrylic acid . By contrast though, Cinnamaverine was claimed to function as a Local anaesthetic, antispasmodic agent.
It does need to be said though that saponification of Triphenylacrylonitrile would also yield the Triphenylacrylic acid. It is worth pointing out that this compound was made by a reaction that is called a Knoevenagel condensation.