Collect. Czech. Chem. Commun. 1981, 46, 933-940

Preparation of conjugates of uridine with proteins by the imido ester condensation method

Helmut Pischela, Antonín Holýb and Günther Wagnera

a Sektion Biowissenschaften-Pharmazie, Karl-Marx-Universitat, Leipzig, G.D.R.
b Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


Reaction of 5'-O-p-toluenesulfonyl-2',3'-O-isopropylideneuridine (I) with sodium 4-cyanophenoxide afforded 2',3'-O-isopropylidene-5'-O-(4-cyanophenyl)uridine (II) which was converted by acid hydrolysis into 5'-O-(4-cyanophenyl)uridine (IIIa). Acid-catalyzed addition of ethanol to compound IIIa gave the imido ester hydrochloride IIIb which on reaction with ammonia or ethylamine was transformed into the amidine derivatives IIIc and IIId. Compound IIIb reacted with human serum albumine or bovine gamma-globuline at pH 9.2 to give protein conjugates with uridine, bound covalently by an amidine bond (IIIe,f).