Synthesis of tyrosine-derived diphenol monomers

Abstract

A method for preparing diphenol compounds, which method includes the steps of coupling a hydroxyphenyl carboxylic acid with a L-tyrosine ester in a water-miscible organic reaction solvent containing a carbodiimide capable of forming a water-soluble urea by-product, thereby forming a diphenol reaction product; and combining the reaction mixture with an amount of water effective to precipitate the diphenol as a water-immiscible organic phase, so that a water-immiscible organic phase is formed containing the diphenol reaction product. New diphenol monomers and polymers polymerized therefrom are also discussed.

What is claimed is:  
     
       1. An L-tyrosine-derived diphenol compound having the structure:                    
       wherein R 1  is selected from the group consisting of —CH═CH—, —CH 2 —, and (—CH 2 —) n , in which n is zero, one,  or an integer from three to eight; and R 2  is selected from the group consisting of straight and branched alkyl and alkylaryl groups containing up to 18 carbon atoms. 
     
     
       2. The diphenol of  claim 1 , wherein R 1  is —CH 2 —. 
     
     
       3. The diphenol of  claim 1 , wherein R 1  is (—CH 2 —) n , in which n is zero or three. 
     
     
       4. The diphenol compound of  claim 1 , wherein R 2  is selected from the group consisting of ethyl, butyl, hexyl, octyl and benzyl groups. 
     
     
       5. The diphenyl compound of  claim 4 , wherein R 2  is a ethyl group. 
     
     
       6. A polycarbonate polymerized from the diphenol compound of  claim 1 . 
     
     
       7. A polyarylate polymerized from the diphenol compound of  claim 1 . 
     
     
       8. A tissue compatible bioerodable polymer polymerized from an L- tyrosine - derived diphenol compound, wherein said diphenol compound has the structure:                      
         wherein R   1    is —CH═CH— or  ( —CH   2   — ) n   , in which n is  0  or an integer from  1  to  8 ; and R   2    is selected from the group consisting of straight and branched alkyl and alkylaryl groups containing up to  18  carbon atoms.   
     
     
       9. The polymer of  claim 8 , wherein R 1    is  ( —CH   2   — ) n   .   
     
     
       10. The polymer of  claim 8 , wherein R 2    is an ethyl, butyl, hexyl, octyl or benzyl group.   
     
     
       11. The polymer of  claim 10 , wherein R 2    is an ethyl group.   
     
     
       12. The polymer of  claim 8 , characterized by being a polyiminocarbonate. 
     
     
       13. The polymer of  claim 8 , characterized by being a polythiocarbonate. 
     
     
       14. The polymer of  claim 8 , characterized by being a polyether.