One-pot synthesis of N-formyl-O-acyl- threo- and erythro-DL-beta-phenylserine ethyl esters and their antiviral properties

A series of N-formyl-O-acyl-beta -phenylserine derivatives 1b-7b were prepa red by the interaction of N-acyl-beta -phenylserine ethyl esters 1a-7a with formic acid in presence of 1.5% HE One-pot acyl group N -->O migration fol lowed N-formylation under elaborated reaction conditions. The kinetics of t he reaction was investigated. The carboxylic acid moiety in the structure o f beta -phenylserine had a strong influence on the reproduction of the used test-viruses. The toxicity and antiviral activity is dependent on the dias tereomeric forms of evaluated compounds.