SYNTHESIS OF TYROSINE DERIVED DIPHENOL MONOMERS

A method for preparing diphenol compounds includes adding a hydroxyphenyl carboxylic acid, a tyrosine ethyl ester, hydroxybenzotriazole hydrate and a solvent and stirring to produce a first solution. EDCI HCl is added to the first solution to produce a first mixture. Ethyl acetate is added to the first mixture to produce a second mixture. The second mixture is added to sodium chloride to produce a third mixture having layer separation. An aqueous layer is removed from the third mixture. The third mixture is extracted with reagents after the aqueous layer has been removed from the third mixture to produce a fourth mixture. Magnesium sulfate is added to the fourth mixture to produce a fifth mixture. The fifth mixture is filtered to produce filtrate. The filtrate is concentrated. Crystallization of the concentrated filtrate is induced. Methylene chloride is added to the crystallized filtrate to produce a solid product.