Alkenylidene bisphenols, a new class of bisphenol bactericide

Alkenylidene bisphenols are prepared by condensation of an appropriate phenol with a haloacetaldehyde, followed by base-induced elimination, or by condensation of the corresponding aryl methyl ether, elimination, and deprotection of the phenol with boron tribromide. The resulting compounds may be further elaborated by reactions on the aromatic nucleus. A series of 13 such compounds showed activity against Staphylococcus aureus; the most active was 1,1-dichloro-2-(3-allyl-5-chloro-2-hydroxphenyl)-2-(5-chloro-2-hydroxyphenyl)ethylene (16), MIC 0.16 microgram/mL. 1,1-Dichloro-2,2-bis(5-chloro-2-hydroxyphenyl)ethylene (6) was similar in its activity and spectrum to hexachlorophene.