Intermediate products for antivirotics and process for preparing them

摘要

It is disclosed a process for the preparation of 1-nitro-4-oxobutanylamides of general formula Ia and Ib
or opposite enantiomers thereof,
wherein R1 is H, alyl, alkyloxycarbonyl, arylalkyloxycarbonyl with a number of carbon atoms up to 24, or the same as in R2, R2 represents alkyl, cycloalkyl or phenylalkyl with up to 24 carbon atoms, and R3 represents alkyl, alkylphenyl, phenylalkyl or phenyl, substituted phenyl, alkoxyphenylalkyl with up to 24 carbon atoms, by the reaction of the
with 2-nitroethenylamides of general formula IIIa and/or IIIb,
where R1, R2 and R3 are as cited above,
in the presence of organic catalysts and co-catalysts in organic solvent, water, in solution of inorganic salts in water or in the mixture of organic solvents and water or in the mixture of solutions of inorganic salts in water and organic solvents at the temperature between -20 and +50 °C.